Choose the best answer:
I felt nervous when the teacher said she __________ my school report home soon.

 

Choose the best answer:
Ba said he ............... some good marks the semester before.

Read the following passage and choose the best answer (A, B, C, D):
According to the American Red Cross, there’s a 97% chance that someone you know will need a blood transfusion. Blood donors — especially donors with certain blood types — are always in demand. To donate blood, the American Red Cross requires that people be at least 17 years old and weigh more than 110 pounds. (In some states, the age is 16 with a parent’s permission.) Donors must be in good health and will be screened for certain medical conditions, such as anemia. Donors who meet these requirements can give blood every 56 days. Blood donation starts before you walk in the door of the blood bank. Eat a normal breakfast or lunch — this is not a good time to skip meals — but stay away from fatty foods like burgers or fries. And be sure to drink plenty of water, milk, or other liquids. Before donating, you’ll need to answer some questions about your medical history, and have your temperature, pulse, blood pressure, and blood count checked. The medical history includes questions that help blood bank staff decide if a person is healthy enough to donate blood. They’ll probably ask about any recent travel, infections, medicines, and health problems. Donated blood gets tested for viruses, including HIV (the virus that causes AIDS), hepatitis B, hepatitis C, syphilis, and West Nile virus. If any of these things are found, the blood is destroyed. Because blood can be infected with bacteria as well as viruses, certain blood components are tested for contamination with bacteria as well.  Are there any risks? A person can’t get an infection or disease from giving blood. The needles and other equipment used are sterile and they’re used only on one person and then thrown away. The U.S. Food and Drug Administration (FDA) regulates U.S. blood banks. All blood centers must pass regular inspections in order to keep operating. Sometimes people who donate blood notice a few minor side effects like nausea, lightheadedness, dizziness, or fainting, but these symptoms usually go away quickly. The donor’s body usually replaces the liquid part of blood (plasma) within 72 hours after giving blood. It generally takes about 4–8 weeks to regenerate the red blood cells lost during a blood donation. An iron-fortified diet plus daily iron tablets can help rebuild a donor’s red blood supply. The Red Cross estimates that 15% of all blood donors in the United States are high school or college students — an impressive number when you consider you have to be 16 or 17 to donate blood. If you are eligible and want to donate blood, contact your local blood bank or the American Red Cross for more information on what’s involved. You could save someone’s life.  
3. According to the passage, which sentence is TRUE about blood donation?

Choose the best answer:
The reporter is talking about the ____________ of the fire.

Choose the best answer:
I enjoy _________ to classical music in my free time.

Read the following passage and choose the best answer (A, B, C, D):
Political and economic reforms launched in 1986 have transformed the country from  one of the poorest in the world, with per capita income around US $100, to lower middle income status within a quarter of a century with per capita income of around US$ 2,100 by the end of 2015.  Vietnam’s per capita GDP growth since 1990 has been among the fastest in the world, averaging 5.5 percent a year since 1990, and 6.4 percent per year in the 2000s. Vietnam’s economy continued to strengthen in 2015, with estimated GDP growth rate of 6.7 percent for the whole year.  The Vietnamese population is also better educated and has a higher life expectancy than most countries with a similar per capita income. The maternal mortality ratio has dropped below the upper-middle-income country average, while under-five mortality rate has fallen by half, to a rate slightly above that average. Access to basic infrastructure has also  improved substantially. Electricity is now available to almost all households, up from less than half in 1993. Access to clean water and modern sanitation has risen from less than 50 percent of all households to more than 75 percent.  Vietnam’s Socio-Economic Development Strategy (SEDS) 2011-2020 gives attention to structural reforms, environmental sustainability, social equity, and emerging issues of macroeconomic stability. It defines three “breakthrough areas”: promoting human resources/skills development (particularly skills for modern industry and innovation), improving market institutions, and infrastructure development. In addition, the five-year Socio-Economic Development Plan 2011-2015 focused on three critical restructuring areas - the, banking sector, state-owned enterprises and public investment that are needed to achieve these objectives. The recent draft of the SEDP 20162020 acknowledges the slow progress of the reform priorities of the SEDP 2011-2015. With agriculture still accounting for almost half the labor force, and with significantly lower labor productivity than in the industry and services sectors, future gains from structural transformation could be substantial. The transformation from state to private ownership of the economy is even less advanced. The state also wields too much influence in allocating land and capital, giving rise to heavy economy wide inefficiencies. So, adjusting the role of the state to support a competitive private sector-led market economy remains a major opportunity. This will be important for enhancing productivity growth which has been stagnating for a long time.
5. According to the passage, what is NOT an example of “breakthrough areas”?

Read the following passage and choose the best answer (A, B, C, D):
Globalization can be seen as increased economic, cultural and technological exchange between countries. Examples might be McDonald's in Calcutta and Japanese motor technology in Britain. Many international organizations are pro-globalization, while many others are anti- ones. The main organizations against globalization are the environmental organizations, such as Friends of the Earth and reenpeace, who put forward the belief that globalization harms the environment. In general, these organizations blame global corporations for global warning and the depletion of natural resources. The most obvious is oil and gas, but there are others such as tropical rainforests, which are cut down for timber, and the resources of the sea, which may be affected by pollution. Organizations which represent developing countries, including international aid agencies such as Oxfam, are also against globalization. They are concerned that the global organizations, such as the International Monetary Fund (IMF) and the World Bank, are not doing enough to help the poor and indeed, may be adding to their problems. Some are critical of the World Trade Organization (WTO). They argue that the WTO is making difficult for poor countries to protect and build their own industries. On the contrary, many organizations are in favor of globalization. Perhaps the most important one is the WTO. This organization was set up in 1995 and has 123 member countries. It administers the rules of international trade agreed by its member countries. The WTO's rules make it difficult for a country to favor their own industry over imports from other countries. The WTO argues that the growth of trade between countries increases the wealth of everyone. Trade allows those who can produce goods most cheaply to do so, thus giving everyone the best possible price. Another pro-globalization organization is IMF. This was established after World War II in 1946. It aims to promote international cooperation on finance and provide temporary help for countries suffering financial problems. The IMF has 182 member countries. Finally, the United Nations, which was established after the Second World War, has become a promoter of globalization. It aims to  promote a shared set of values in the areas of labour standards, human rights and environmental practices between the UN and the business community.
4. The word "others" in paragraph 2 refers to: 

Read the following passage and choose the best answer (A, B, C, D):
When hosting an Olympic Games, a country has to take account of several considerations, among which the financial one is by far the most important. The costs of hosting the Olympics can (1) _______ tens of billions of dollars, and it is commonplace for budgets to double or even triple. In addition to the direct costs of hosting the Games (the opening and closing ceremonies, athletes’ village, security, etc.), cities often must build expensive new venues (2) _______ lesser-known sports. Once constructed, sports venues often incur additional maintenance costs long after the Games have ended. While costs are the (3) _______ concern for a host city, there are other factors to consider. For one, an Olympic host city may receive substantial revenue from ticket sales, tourist spending, corporate sponsorship, and television rights. Cities such as Los Angeles (1984) and Seoul (1988) actually made a large profit from the Games they hosted. (4) _______, hosting the Olympic Games confers prestige on a host city and country, which can lead to increased trade and tourism. The Olympics are also an opportunity to invest in projects (5) _______ improve the city’s quality of life, such as new transportation systems

Read the following passage and choose the best answer (A, B, C, D):
Spend just a minute watching the world population counter tick up on Worldometers and you’ll see just how quickly we’re swelling in numbers. The current figure stands at around 7.7 billion, and this is projected to become 9.8 billion by 2050, according to the UN. More people means more carbon footprints - more cars, waste and emissions, more houses and infrastructure to be constructed using the world’s limited resources, more mouths to be fed using more water and energy in food production. Governments recognise the severity of the situation and have mostly come together over global policies like the UN’s Paris Agreement, to limit carbon emissions and their impact on climate change. In addition, new technologies are being developed to make our use of resources more efficient. As for controlling population growth, the education of women is one key factor. Research shows the higher level to which a woman is educated, the fewer children she is likely to have. In Ghana, for example, women who have been to high school, have a fertility rate of between two and three children, compared with six for those who have no education. This could be for several reasons including learning about desired family size and understanding child health better. This means that the mother is more confident her children will survive. She is also likely to hold more sway within the family, arguing for fewer children if that is what she wants.  There is also plenty that individuals can do to reduce their personal footprint. Earth Overshoot Day is defined as the day when humanity has used up nature’s resource budget for the year. The Global Footprint Network calculates that moving Earth Overshoot day back by five days every year would mean that, by 2050, we’d be using the resources of less than one planet. Just eating 50% less meat and replacing it with vegetarian alternatives could save the planet five days. As David Attenborough says, if we want to save Earth, we can no longer afford to keep eating meat: “We are omnivores, so biologically, if you could have a biological morality, you can say, yes we evolved to eat pretty well everything. But now we’ve got to a stage in our own social evolution in which that is no longer practical.” Sir David says he himself now eats less meat and is bolstered by the knowledge that it’s helping the planet.  
3. According to paragraph 2, what is NOT mentioned as the cause of rise in the amount of CO2 emission?

Read the following passage and choose the best answer (A, B, C, D):
Nowadays, dozens of interventions are known that extend the lifespan of various living organisms ranging from yeast to mammals. They include chemical compounds, genetic interventions, and diets. Some targets of these interventions have been discovered. However, there is still no clear understanding of the systemic molecular mechanisms leading to lifespan extension. A group of scientists from Skoltech, Moscow State University and Harvard University decided to fill this gap and identify crucial molecular processes associated with longevity. To do so, they looked at the effects of various lifespan-extending interventions on the activity of genes in a mouse, a commonly used model organism closely related to humans. “In our lab, we subjected mice of different sexes and ages to 8 longevity interventions and analyzed gene expression changes induced by these treatments. After aggregating our data with the datasets published by other groups, we obtained gene activity profiles of 17 interventions. Although in general the effects produced by individual treatments turned out to be rather specific, a certain group of genes changed its expression in a similar way in response to different lifespan-extending interventions,” says the first author of the study, Alexander Tyshkovskiy. The scientists then applied the discovered biomarkers to search for other interventions with the same effect on their activity and, therefore, high potential for lifespan extension "Currently, we are validating these hits by testing their effect on the mouse lifespan. We hope that our biomarkers will significantly facilitate the search for new longevity interventions and help improve the healthspan and lifespan in rodents and, in the long term, in humans," says Alexander. 
5. The word “validating” in paragraph 4 is closest in meaning to ______

Read the following passage and choose the best answer (A, B, C, D):
Children’s behaviour has worsened over the past five years, according to a survey of  teachers which found that a fifth thought girls were more likely to cause trouble than boys. The survey, published after teachers at a Lancashire school went on strike over discipline, found low-level disruption, including chatting and “horsing around”, was the biggest problem. Boys were more likely to be physically aggressive while girls tended to ostracise other pupils. The behaviour of boys was more of a challenge than that of girls but the actions of each sex had deteriorated, according to 56.5% of staff surveyed by the Association of Teachers and Lecturers (ATL).  Among male pupils the most challenging behaviour for teachers was physical aggression, such as pushing, spitting, kicking and hitting. A secondary teacher quoted in the survey said boys were usually aggressive with other pupils, while girls tended to call one another names. Teachers criticised a lack of role models in the home. A primary teacher said: “The boys are far more willing to be aggressive to adults, verbally and even physically. There don’t seem to be any parental boundaries set of what is an appropriate way to speak and deal with another adult.” Teachers at Darwen Vale high school, Lancashire, walked out over unruly pupil behaviour this month. They said children challenged them to fights and threatened to film lessons and post them online. The survey of more than 850 teachers, heads and other school staff found that more than 21% thought girls’ behaviour was more challenging than boys, compared with 68% who said male pupils caused more trouble. In schools that have excluded pupils, 57% said more boys and 5% said more girls had been excluded. A department head in a primary school told the survey, carried out in March, that “classes with a majority of boys tend to be louder, less co-operative and harder to teach”. Nearly half of the staff surveyed said boys’ bravado was behind their disruption. For girls, the most likely trigger was a break-up between friends. A primary school teacher from Bedfordshire said: "Boys are generally more physical and their behaviour is more noticeable. Girls often say nasty things, which end up disrupting the lesson just as much as the boys, as other children get upset and can’t focus on their work. They are usually the ones who refuse to comply with instructions." Some staff had noticed girls’ behaviour worsening.” A teaching assistant from Weston-super-Mare said: “Girls are definitely getting more violent, with gangs of girls in school who are getting worse than the gangs of boys.” The ATL annual conference in Liverpool on Monday is due to debate a motion expressing concern at increasing numbers of girls being excluded from secondary school.  Government figures for 2008-9 showed that boys represented 78% of the total number of permanent exclusions from schools in England. This proportion was unchanged from the year before. The ATL general secretary, Mary Bousted, said: "Staff get ground down daily by the chatting and messing around, which disrupts lessons for other pupils and takes the pleasure out of teaching. Even more worrying is the physical aggression, most often among boys but also among some girls, which puts other pupils and staff at risk. Schools need to have firm and consistent discipline policies and work with parents to keep schools and colleges safe places for pupils and staff alike." The education bill, now going through the Commons, will give teachers the right to search pupils for banned items and will remove the requirement to give parents a day’s notice of detention. The education secretary, Michael Gove, said the measures in the bill would “restore discipline” in the classroom.
3. Which of the following is NOT true about the schoolboys in paragraph 2?

Read the following passage and choose the best answer (A, B, C, D):
Money habits matter a lot in a relationship, even if you’re not married or living together, concludes Melissa A Curran, an associate professor at the University of Arizona, in a new study published in the Journal of Family and Economic Issues. That’s why she recommends being picky when it comes to dating. “Young adults should choose their romantic partner wisely,” Curran tells CNBC Make It. She and her colleagues assessed over 500 young twenty-somethings in committed relationships and had them rate their health and overall life satisfaction. She asked them questions related to their partners’ financial responsibility, such as, Do they spend within a budget? And, Do they usually pay off their credit cards in full? The researchers found that the more responsible the participants perceived their partners to be with money, the higher their own sense of well-being and the happier they were with their relationships. The opposite was also true. Participants who thought their partners were bad with money had a lower sense of well-being and felt less committed to the relationship. “This finding makes sense developmentally as the young adults are transitioning to adulthood,” says Curran. “It would make sense for them to draw upon romantic partners in terms of financial socialization agents.” By socialization agents, she means people who can teach and influence the participants on matters related to money. The idea is that the financial habits of whoever you’re dating can rub off on you. If your partner is bad with money, you might become bad with money too, which in turn affects your life overall, since the researchers also confirmed that your own financial habits definitely affect your well-being. For many young adults, parents are the most influential socialization agents. So, in this study, Curran also asked the participants about what their parents expected of them when it came to their finances. Did their parents, for example, expect them to track their spending? The researchers found that high expectations from an involved parent led the participants to perform better on a financial literacy test. But, unlike romantic partners, they did not seem to influence well-being. If you’re bothered by your significant other’s over-spending or general irresponsibility with money, Curran and her colleagues recommends talking things through. “Having discussions about finances and making financial decisions together helps couples become closer and more satisfied with their relationships.”
2. The word “picky” in paragraph 1 is closest in meaning to _______

Read the following passage and choose the best answer (A, B, C, D):
There’s a direct link between employee satisfaction and customer satisfaction.  Employees are the driving factor behind customer satisfaction. Employee interactions set the tone for a positive or negative customer experience. When employees aren’t happy at work, their interactions with customers can, and almost always will, suffer. Over the course of time, this can have serious repercussions for a business. The place where this becomes the most critical is any business where employees are directly interacting with customers, such as retail or food service. Historically underpaid and overworked, employees in these jobs are tasked with spending their entire shifts serving customers.  This is where employee experience comes in. If even a fraction of a customer experience budget was spent on employee experience, there would be a huge return on investment. One of the easiest ways to enhance employee experience is to ask for and welcome employees’ feedback. They have great insight into customer needs. After all, they’re the ones who are directly interacting with customers and hearing their criticisms and compliments firsthand. Employees can be your biggest asset when it comes to customer satisfaction.  A large part of employee experience revolves around understanding what employees need and want and gaining insight into their work preferences. Another critical piece of the employee experience is training and development. Employees should be equipped with the skills they need to excel at their jobs and have opportunities to continue to learn and develop. They should be able to check in and touch base with their managers to keep track of their progress and discuss any questions or concerns as they arise. Showing employees that you value the work they’re doing is one of the easiest ways to boost their motivation. It can be as simple as saying thank you, to publicly acknowledging and celebrating their contributions. It’s not just the younger generations who crave recognition - no one likes to feel like the work they’re doing is going unnoticed.  It’s time to shift the mindset from employees working just to work, to acknowledging that they’re valuable contributors to a company’s success. Employees need to understand how important their role is and how their work fits into the bigger picture. They need to feel like their voices are being heard and they have respect from their managers. Most importantly, they need to be able to come to work and know that the next eight hours won’t be pure torture. 
7. Which of the following statements is TRUE, according to the passage?

Read the following passage and choose the best answer (A, B, C, D):
Parents in most cases want the best for their children, and to ensure this, they are  pushed to actively engage in their children’s lives, to ensure that they are making the right choices. Some parents, however, go to the extent of wanting to have the upper hand even when it comes to taking major decisions, such as choosing a career.  Local comedian and actor, Michael Sengazi, was obliged by his parents to pursue a career in law, a path he followed when he joined University of Kigali, but deep down he knew this wasn’t his dream career. This is why after graduating he chose to follow his passion —comedy. His parents failed to understand how a qualified lawyer could decide to go for comedy because they didn’t see it as a ‘well-paying job’. He had a challenge of convincing them to bless his journey. “So, I asked them to give me one year to try and see if comedy would work out for me. I worked hard and my parents realised that I could achieve big things, and they gave me the freedom to pursue the career.”  Bienvenue Muragwa, a career consultant at The Southern New Hampshire University based in Rwanda, says that parents are only allowed to guide the child during the career guidance process, but not take the final decision. “Parents are not allowed to choose or take the final decision for their children as the performance of the student is the assessing parameter of the career to be pursued,” he explains.  Shalom Azabe, a graduate in general counselling at Kampala Christian University, says in most African countries, not only Rwanda, children are overly dependent on their parents, yet this shouldn’t be the case. She recommends picking a leaf from westerners who endeavour to learn their children’s interests, something she says aides them in career guidance for the child. “Normally, a child starts to demonstrate a choice in career at 14 years of age. This is when parents need to sit down and make analysis that would help them guide their child in choosing the fitting option to undertake. This is in fact considered as overprotection as parents want to exercise their authority on their kids unwillingly, yet this affects them psychologically, and when the kid later on fails, they encounter a regret of pursuing studies that were not their choice in the first place,” Azabe said.
4. The word “parameter” in paragraph 3 can be replaced by_______

Read the following passage and choose the best answer (A, B, C, D):
“Parents today want their kids spending time on things that can bring them success, but (1) ___________, we’ve stopped doing one thing that’s actually been a proven predictor of success—and that’s household chores,” says Richard Rende, a (2)_________ psychologist in Paradise Valley, Ariz., and co-author of the forthcoming book “Raising Can-Do Kids.” Decades of studies show the benefits of chores—academically, emotionally and even professionally. Giving children household chores at an early age (3)_____ to build a lasting sense of mastery, responsibility and self-reliance, according to research by Marty Rossmann, professor emeritus at the University of Minnesota. In 2002, Dr. Rossmann analyzed data from a longitudinal study (4)____________ followed 84 children across four periods in their lives—in preschool, around ages 10 and 15, and in their mid-20s. She found that young adults who began chores at ages 3 and 4 were more likely to have good relationships with family and friends, to achieve academic and early career success and to be self-sufficient, as (5)__________ with those who didn’t have chores or who started them as teens. Chores also teach children how to be empathetic and responsive to others’ needs, notes psychologist Richard Weissbourd of the Harvard Graduate School of Education.

Read the following passage and choose the best answer (A, B, C, D):
“Parents today want their kids spending time on things that can bring them success, but (1) ___________, we’ve stopped doing one thing that’s actually been a proven predictor of success—and that’s household chores,” says Richard Rende, a (2)_________ psychologist in Paradise Valley, Ariz., and co-author of the forthcoming book “Raising Can-Do Kids.” Decades of studies show the benefits of chores—academically, emotionally and even professionally. Giving children household chores at an early age (3)_____ to build a lasting sense of mastery, responsibility and self-reliance, according to research by Marty Rossmann, professor emeritus at the University of Minnesota. In 2002, Dr. Rossmann analyzed data from a longitudinal study (4)____________ followed 84 children across four periods in their lives—in preschool, around ages 10 and 15, and in their mid-20s. She found that young adults who began chores at ages 3 and 4 were more likely to have good relationships with family and friends, to achieve academic and early career success and to be self-sufficient, as (5)__________ with those who didn’t have chores or who started them as teens. Chores also teach children how to be empathetic and responsive to others’ needs, notes psychologist Richard Weissbourd of the Harvard Graduate School of Education

Choose the best answer:
Two months ago my brother _______ elected headmaster of his school and he _______ a vacation since then.

Mark the letter A, B, C, or D on your answer sheet to indicate the undelined part that needs correction in each of the following questions:
These days, most people in Britain and the US do not wear very formal clothes. But sometimes it is important to wear the right thing.
Many British people don't think about clothes very much. They just like to be comfortable. When they go out to enjoy themselves, they can wear almost anything. At theatres, cinemas and concerts you can put on what you like from elegant suits and dresses to jeans and sweaters. Anything goes, as long as you look clean and tidy.
But in Britain, as well as in the US, men in offices usually wear suits and ties, and women wear dresses or skirts (not trousers). Doctors, lawyers and business people wear quite formal clothes. And in some hotels and restaurants men have to wear ties and women wear smart dresses.
In many years, Americans are more relaxed than British people, but they are more careful with their clothes. At home, or on holiday, most Americans wear informal or sporty clothes. But when

they go out in the evening, they like to look elegant. In good hotels and restaurants, men have to wear jackets and ties, and women wear pretty clothes and smart hairstyles.
It is difficult to say exactly what people wear informal or formal in Britain and the US, because everyone is different. If you are not sure what to wear, watch what other people do and then do the same. You'll feel more relaxed if you don't look too different from everyone else.

Who doesn’t usually wear suits and ties?

Mark the letter A, B, C, or D on your answer sheet to indicate the undelined part that needs correction in each of the following questions:
There are three valid arguments to support the preservation of endangered species. An aesthetic justification contends that biodiversity contributes to the quality of life because many of the endangered plants and animals are particularly appreciated for their unique physical beauty. The aesthetic role of nature in all its diverse forms is reflected in the art and literature of every culture, attaining symbolic status in the spiritual life of many groups. According to the proponents of the aesthetic argument, people need nature in all its diverse and beautiful forms as part of the experience of the world.
Another argument that has been put forward, especially by groups in the medical and pharmacological fields, is that of ecological self-interest. By preserving all species, we retain a balance of nature that is ultimately beneficial to humankind. Recent research on global ecosystems has been cited as evidence that every species contributes important or even essential functions that may be necessary to the survival of our own species. Some advocates of the ecological argument contend that important chemical compounds derived from rare plants may contain the key to a cure for one of the diseases currently threatening human beings. If we do not protect other species, then they cannot protect us.
Apart from human advantage in both the aesthetic and ecological arguments, the proponents of a moral justification contend that all species have the right to exist, a viewpoint stated in the United Nations World Charter for nature, created in 1982. Furthermore, if humankind views itself as the stewards of all the creatures on Earth, then it is incumbent upon human beings to protect them, and to ensure the continued existence of all species. Moral justification has been extended by a movement called “deep ecology,” the members of which rank the biosphere higher than people because the continuation of life depends on this larger perspective. To carry their argument to its logical conclusion, all choices must be made for the biosphere, not for people.

The word “perspective” in paragraph 3 could best be replaced by    .

Read the following passage and choose the best answer (A, B, C, D):
When you first arrive in a foreign culture, often your first reaction is completely positive. Everything seems exciting, different and fascinating. It’s an (1) ______. If you are just on a short holiday, you will probably never leave this phase. (2) ______, if you stay longer, your attitude can start to change. As you start to realize (3) ______ little you really understand the new culture, life can get frustrating. People misunderstand what you are trying to say, or they may laugh at you when you say something incorrectly. Even simple things, like posting a letter, can seem very difficult to you. Thus, you are likely to get angry or upset when things go wrong. With time, though, you start to (4) ______ to become more comfortable with the differences and better able to handle frustrating situations. Your (5) ______ of humor reappears. Finally, you may feel enthusiastic about the culture once again, enjoy living in it, and even prefer certain aspects of the culture to your own.

Mark the letter A, B, C, or D on your answer sheet to indicate the undelined part that needs correction in each of the following questions:
Pollution is a threat to many species on Earth, but sometimes it can cause species to thrive. Such is the case with Pfiesteria piscicida. A one-celled creature called a dinoflagellate, Pfiesteria inhabits warm coastal areas and river mouths, especially along the eastern United States. Although scientists have found evidence of Pfiesteria in 3,000-year-old sea floor sediments and dinoflagellates are thought to be one of the oldest life forms on earth, few people took notice of Pfiesteria.
Lately, however, blooms – or huge, dense populations – of Pfiesteria are appearing in coastal waters, and in such large concentrations the dinoflagellates become ruthless killers. The blooms emit powerful toxins that weaken and entrap fish that swim into the area. The toxins eventually cause the fish to develop large bleeding sores through which the tiny creatures attack, feasting on blood and flesh. Often the damage is astounding. During a 1991 fish kill, which was blamed on Pfiesteria on North Carolina’s Neuse River, nearly one billion fish died and bulldozers had to be brought in to clear the remains from the river. Of course, such events can have a devastating effect on commercially important fish, but that is just one way that Pfiesteria causes problems. The toxins it emits affect human skin in much the same way as they affect fish skin. Additionally, fisherman and others who have spent time near Pfiesteria blooms report that the toxins seem to get into the air, where once inhaled they affect the nervous system, causing severe headaches, blurred vision, nausea, breathing difficulty, short-term memory loss and even cognitive impairment.
For a while, it seemed that deadly Pfiesteria blooms were a threat only to North Carolina waters, but the problem seems to be spreading. More and more, conditions along the east coast seem to be favorable for Pfiesteria. Researchers suspect that pollutants such as animal waste from livestock operations, fertilizers washed from farmlands and waste water from mining operations have probably all combined to promote the growth of Pfiesteria in coastal waters.

What is the main function of the toxins emitted by the dinoflagellates?

Find synonym:
They can enjoy the -comfort and elegance of five-star hotels and luxury cruise ships.