Read the following passage and do the tasks below.

Southeast Asian Countries’ PISA Rankings 2012

Once every three years, 15-year-olds from around the world are tested on how well they know their reading, maths and science. This is called the Programme for International Student Assessment, or PISA for short. It is run by the Organization for Economic Coopertation and Development or OECD. Over half a million students from 65 countries and economies took part in PISA 2012. The result of the latest PISA 2012 had been announced on 3 December 2013. Only five out of ten ASEAN countries participated in PISA 2012. They were Indonesia, Malaysia, Singapore, Thailand and Vietnam.
- Singapore ranked 2nd in maths and 3rd in reading and science;
- Vietnam, entered PISA tests for the first time, ranked 8th in science, 17th in maths and 19th in reading;
- Thailand has been the participant in the PISA tests since 2000. It ranked 47 in science, 48th in reading and 50 in maths;
- Malaysia got 52th in maths, 53rd in science and 59th in reading;
- Indonesia got 61st in reading and got 64th in maths and science.
Singapore’s 15-year-old students came in the top five in every area. Vietnamese students scored very well on all three PISA subjects. Thailand, Indonesia and Malaysia ranked below average for the 65 countries assessed. The next administration of PISA is in 2015 and results will be reported at the end of 2016.

What does PISA stand for?

Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.

In American, although most men still do less housework than their wives, that gap has been halved since the 1960s. Today, 41 per cent of couples say they share childcare equally, compared with 25 percent in 1985. Men's greater involvement at home is good for their relationships with their spouses, and also good for their children. Hands-on fathers make better parents than men who let their wives do all the nurturing and childcare. They raise sons who are more expressive and daughters who are more likely to do well in school - especially in math and science.

In 1900, life expectancy in the United States was 47 years, and only four per cent of the population was 65 or older. Today, life expectancy is 76 years, and by 2025, it is estimated about 20 per cent of the U.S. population will be 65 or older. For the first time, a generation of adults must plan for the needs of both their parents and their children. Most Americans are responding with remarkable grace. One in four households gives the equivalent of a full day a week or more in unpaid care to an aging relative, and more than half say they expect to do so in the next 10 years. Older people are less likely to be impoverished or incapacitated by illness than in the past, and have more opportunity to develop a relationship with their grandchildren.

Even some of the choices that worry people the most are turning out to be manageable. Divorce rates are likely to remain high, and in many cases marital breakdown causes serious problems for both adults and kids. Yet when parents minimize conflict, family bonds can be maintained. And many families are doing this. More non-custodial parents are staying in touch with their children. Child-support receipts are rising. A lower proportion of children from divorced families are exhibiting problems than in earlier decades. And stepfamilies are learning to maximize children's access to supportive adults rather than cutting them off from one side of the family.

Nowadays, ____ of men help take care of children.

Homing pigeons are placed in a training program from about the time they are twenty-eight days of age. They are taught to enter the loft through a trap and to exercise above and around the loft, and gradually they are taken away for short distances in wicker baskets and released. They are then expected to find their way home in the shortest possible time. In their training flights or in actual races, the birds are taken to prearranged distant points and released to find their way back to their own lofts. Once the birds are liberated, their owners, who are standing by at the home lofts, anxiously watch the sky for the return of their entries. Since time is of the essence, the speed with which the birds can be induced to enter the loft trap may make the difference between gaining a win or a second place.
The head of a homing pigeon is comparatively small, but its brain is one quarter larger than that of the ordinary pigeon. The homing pigeon is very intelligent and will persevere to the point of stubbornness some have been known to fly a hundred miles off course to avoid a storm.
Some homing pigeon experts claim that this bird is gifted with a form of built-in radar that helps it find its own loft after hours of flight, for hidden under the head feathers are two very sensitive ears, while the sharp, prominent eyes can see great distances in daytime.
Why do homing pigeons fly home? They are not unique in this inherent skill: it is found in most migratory birds, in bees, ants, toads, and even turtles, which have been known to travel hundreds of miles to return to their homes. But in the animal world, the homing pigeon alone can be trusted with its freedom and trained to carry out the missions that people demand.

According to the passage, what happens to homing pigeons when they are about a month old?

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct  answer to each of the following questions.

A YEAR WITH OVERSEAS VOLUNTEERS

I was with Overseas Volunteers (OV) for a year after leaving university, and I was sent to an isolated village in Chad, about 500 km from the capital N'Djamena. Coming from a rich country, I got quite a shock as conditions were much harder than I had expected. But after a few days I soon got used to living there. The people were always very friendly and helpful, and soon I began to appreciate how beautiful the countryside was.

One of my jobs was to supply the village with water. The well was a long walk away. And the women used to spend a long time every day carrying heavy pots backward and forwards. So I contacted the organization and arranged to have some pipes delivered. We built a simple pipeline and a pump, and it worked the first time. It wasn't perfect - there were a few leaks, but it made a great difference to the villagers, who had never had running water before. And not only did we have running water, but in the evenings it was hot because the pipe had been lying in the sun all day. All in all, I think .my time with OV was a good experience. Although it was not well-paid, it was well worth doing, and I would recommend it to anyone who was considering working for a charity.

How did the author feel when he arrived in the village?

Read the following text and circle the best answer:
(18 April) – MKZ Foods, Inc., the region's largest exporter of pecans,  expects its outgoing shipments to increase significantly over the next few months. This ---143--- is based on the fact that the region's pecan farmers expanded their land area by 20 percent last year.  According to spokesperson Katharina Seiler, MKZ's exports could reach a colossal 50,000 metric tons this year. ---144---. MKZ buys most of the yield from the region's pecan farms and processes it ---145--- export throughout the world. "The availability of new land for ---146--- in the region is creating opportunities for growth," said Ms. Seiler. "I believe MKZ is going to have a truly outstanding year."

145......................

Tulips are Old World, rather than New World, plants, with the origins of the species lying in Central Asia. They became an integral part of the gardens of the Ottoman Empire from the sixteenth century onward, and, soon after, part of European life as well. Holland, in particular, became famous for its cultivation of the flower.
A tenuous line marked the advance of the tulip to the New World, where it was unknown in the wild. The first Dutch colonies in North America had been established in New Netherlands by the Dutch West India Company in 1624, and one individual who settled in New Amsterdam (today's Manhattan section of New York City) in 1642 described the flowers that bravely colonized the settlers' gardens. They were the same flowers seen in Dutch still-life paintings of the time: crown imperials, roses, carnations, and of course tulips. They flourished in Pennsylvania too, where in 1698 William Penn received a report of John Tateham's "Great and Stately Palace”, its garden full of tulips.
By 1760, Boston newspapers were advertising 50 different kinds of mixed tulip "roots”. But the length of the journey between Europe and North America created many difficulties. Thomas Hancock, an English settler, wrote thanking his plant supplier for a gift of some tulip bulbs from England, but his letter the following year grumbled that they were all dead.
Tulips arrived in Holland, Michigan, with a later wave of early nineteenth-century Dutch immigrants who quickly colonized the plains of Michigan. Together with many other Dutch settlements, such as the one at Pella, Iowa, they established a regular demand for European plants. The demand was bravely met by a new kind of tulip entrepreneur, the traveling salesperson. One Dutchman, Hendrick Van De Schoot, spent six months in 1849 traveling through the United States taking orders for tulip bulbs. While tulip bulbs were traveling from Europe to the United States to satisfy the nostalgic longings of homesick English and Dutch settlers, North American plants were traveling in the opposite direction. In England, the enthusiasm for American plants was one reason why tulips dropped out of fashion in the gardens of the rich and famous.

The word “integral" is the closest in meaning to_________.

Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.

Who talks more - men or women? Most people believe that women talk more. However, linguist Deborah Tannen, who has the studied the communication style of men and women, says that this is a stereotype. According to Tannen, women are more verbal - talk more - in private situations, where they use conversation as the “glue’ to hold relationships together. But, she says, men talk more in public situations, where they use conversation to exchange information and gain status. Tannen points out that we can see these difference even in children. Little girls often play with one ‘best friend’ and their play includes a lot of conversation. Little boys often play games in groups, their play usually involves more doing than talking. In school, girls are often better at verbal skills, while boys are often better at mathematics.

A recent study at Emory University helps to shed light on the roots of this difference. Researchers studied conversation between children aged 3-6 and their parents. They found evidence that parents talk very differently to their sons than they do to their daughters. The startling conclusion was that parents use more language with their girls. Specifically, when parents talk with their daughters, they use more descriptive language and more details. There is also far more talk about emotions, especially with daughters than with sons.

Which of the following phrases best explains the meaning of the word “verbal”?

Political and family values within society have impacted upon the modern family structure. Traditionally, it has been the man’s role to be the breadwinner for the family- providing the funds to pay for food and shelter. However, due to the many new and unique responsibilities placed upon families, in numerous cases both men and women- fathers and mothers- have had to enter the workforce. Generally, the reasons for both being involved in the workforce revolve around the need to add to the family’s current financial base. To a lesser extent, the need to interact with “adults” in a stimulating work environment is another popular reason. Whatever their reasons, for many families, the decision for father and mother to go out of home and join the labor force has led to a number of side effects within the home which, in turn, impact upon their performance as employees. Many researchers agree that attitudes towards work are carried over into family life. This spillover can be positive or negative. Positive spillover refers to the spread of satisfaction and positive stimulation at work resulting in high levels of energy and satisfaction at home. If the amount of research is to be taken as an indication, it would seem that positive spillover is not a dominant occurrence in the workplace with most research focusing on the effects of negative spillover. Often pointing out the incompatible nature of work and family life, the research focuses on problems and conflict at work which has the effect of draining and preoccupying the individual, making it difficult for him or her to participate fully in family life.
Social scientists have devised a number of theories in an attempt to explain the work-family dynamic. Compensation theory is one which has been widely used. It assumes that the relationship between work and family is negative by pointing out that high involvement in one sphere- invariably the work sphere- leads to low involvement in the other. As an individual advances within a career, demands typically fluctuate from moderate to more demanding and if the advancing worker has younger children, this shift in work responsibilities will usually manifest itself in the form of less time spent with the family. Researchers subscribing to this theory point out that the drain on family time is significantly related to work-family conflict with an escalation in conflict, as the number of families increase.

The following are the reasons why the fathers and mothers both go to work EXCEPT_______

Sleep is a natural process, and although a lot have been written about the subject, it is still surrounded by mystery. It is used by some as an escape from the world, and regarded by others as an irritating waste of time: some people get by on very little, others claim they cannot exist without at least ten hours, but nobody can do without sleep completely.
Our night’s sleep does not just consist of a steady phase of gradually deepening sleep. It alternates between two stages: Non-dreaming or ordinary sleep, and REM (rapid eye movement) or dreaming sleep. As soon as we fall asleep, we go straight into non-dreaming sleep for an hour or so, then into REM sleep for about 15 minutes, then back into non-dreaming sleep. It alternates in this way for the rest of the night, with non-dreaming sleep tending to last longer at the beginning of the night. Non-dreaming sleep occupies three-quarters of our night’s sleep, about a quarter of it deep and the rest fairly light. 
It is widely believed that sleep repairs the body and makes good the damage caused by being awake. However, its main function is to refresh the brain. Experts believe that probably only about two-thirds of our sleep is necessary for repairing and refreshing the brain, with the most valuable sleep coming in the first few hours of the non-dreaming period, the last few hours of sleep are not so essential. The brain can manage quite well with reduced sleep as long as it is uninterrupted sleep. 
The quality of sleep is important. A study conducted in the USA looked at short sleepers, who slept for 5.5 hours on average, and long sleepers, who had 8.5 hours or more. It is discovered after a variety of tests that the long sleepers were poor sleepers, had twice as much REM sleep as the short sleepers, appeared to sleep longer to make up for poor sleep, and did not wake up in the morning refreshed. Similarly, people who sleep deeply do not necessarily get a better quality of sleep than shallow sleepers. Deep sleepers can feel tired the following day, so six hours of good sleep is worth more than eight hours of troubled sleep.

It can be inferred from the experts’ ideas that ______.

Read the following text and circle the best answer:
Welcome to Arolis Chemicals! Thank you for ---139--- the full-time, permanent position of laboratory assistant. We look forward to your arrival on 1 August in the Harris Building. Please report to the front desk and ask for Jack McNolan. He ---140--- you to the Human Resources office. There, you will obtain your employee badge
---141--- all documents necessary to start work. Note that because of its large size, the Leicester campus of Arolis can be difficult to navigate. Studying a campus map will help orient you to the location of the different buildings.----142---. Should you have any questions, please do not hesitate to contact me.

140...................

Each summer, the Winant and Clayton Volunteer program sends a group of Americans to volunteer in London for seven weeks and provides housing and a small stipend to help defray the high cost of living. After seven weeks of volunteering, participants have two weeks to travel independently before returning to London to evaluate the program and get their flight back to the United States.

The application includes a few short essays, a series of questions about the type of placement one would prefer, and an informal interview with former volunteers that gives applicants a chance to find out more about the program.

Deciding to participate takes a small leap of faith. The roster of volunteer placements and housing options can change from year to year and volunteers can’t choose their placement in advance. But once you’re accepted you instantly feel that you’ve joined a close-knit group. The volunteer coordinator is in frequent contact through mailings and e-mails to help you prepare for the trip, and there is a daylong orientation in New York that bring all the volunteers together before departure for London.

How long do a group of Americans volunteer in London?

Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks.

In a healthy relationship, both partners respect, trust and embrace (1) ____ differences. Both partners are able to communicate (2) ____ their needs and listen to their partner, and work to resolve conflict in a rational and (3) ____ way. But maintaining a healthy relationship (4) ____ for skills many young people are never taught. A lack of these skills, and (5) ____ up in a society that sometimes celebrates violence or in a community that experiences a high (6) ____ of violence, can lead to unhealthy and even violent relationships among youth.

Dating violence (7) ____ psychological or emotional violence, such as controlling behaviours or jealousy; physical violence, such as hitting or punching. More than 20 per cent of all adolescents report having experienced (8) ____ psychological or physical violence from an intimate partner - and underreporting remains a concern.

Adolescents, (9) ____ older adolescents, often have romantic relationships, which are long-term, serious, and intimate. Society has a responsibility to provide young people with the resources, skills, and space (10) ____ to safeguard their physical and emotional well being in these relationships. Youth-serving professionals, educators, and parents can help young people in need access services to (11) ____ dating abuse victimisation. Research also has shown that programmes intended to prevent dating violence can be (12) ____.

(11)....................

Read the following text and circle the best answer:
With Global Strength Gym's 30-day trial period, you get the opportunity to try out our classes, equipment, and facilities.----131---. It's completely risk-free! To sign up, we require your contact information and payment details, but you will only be charged if you are a member for---132--- 30 days. If you decide within this time that you no longer want to be a member of  Global Strength, ---133--- visit our Web site at www.gsgym.com. On the Membership page, elect to ---134--- your membership and enter the necessary information. It's that easy!

134...................

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

The American type of football was developed in the 19th century from soccer and rugby football. Played by professionals, amateurs, college and high school students, or young children, football in American is one of the most popular sports besides basketball and baseball. It attracts millions of fans each fall and people are very supportive of their favourite teams. The football playing field of today is rectangular in shape and measures 100 yards long and 53.5 yards wide. White lines are painted on the playing field to mark off the distances to the end zone. The games is divided into four quarters, each fifteen minutes long. The first two quarters are known as the first half. There is a rest period between two halves which usually last about fifteen minutes. Each team has eleven players. Each team has offensive players who play when the team has possession of the ball and defensive players who play when the other team has the possession of the ball. Because of the body contact players have during the game, helmets are worn to protect their head and face area, whereas pads are worn to protect the shoulders, arms, and legs. Also, there are officials carrying whistles and flags to make certain that the rules of the game are followed during the game. The football is made of leather and is brown in colour. It is shaped much like an oval and has white rings near each end of the football. These rings help the players see the ball when it is thrown or someone is running with it. The eight stitches on the top of the football help the players to grip the ball when throwing or passing. The most famous game of the year is Super Bowl that is played in January or February. It is televised around the world and is watched by millions of people each year.

Playing American football is the most similar to playing....................

Political and family values within society have impacted upon the modern family structure. Traditionally, it has been the man’s role to be the breadwinner for the family- providing the funds to pay for food and shelter. However, due to the many new and unique responsibilities placed upon families, in numerous cases both men and women- fathers and mothers- have had to enter the workforce. Generally, the reasons for both being involved in the workforce revolve around the need to add to the family’s current financial base. To a lesser extent, the need to interact with “adults” in a stimulating work environment is another popular reason. Whatever their reasons, for many families, the decision for father and mother to go out of home and join the labor force has led to a number of side effects within the home which, in turn, impact upon their performance as employees. Many researchers agree that attitudes towards work are carried over into family life. This spillover can be positive or negative. Positive spillover refers to the spread of satisfaction and positive stimulation at work resulting in high levels of energy and satisfaction at home. If the amount of research is to be taken as an indication, it would seem that positive spillover is not a dominant occurrence in the workplace with most research focusing on the effects of negative spillover. Often pointing out the incompatible nature of work and family life, the research focuses on problems and conflict at work which has the effect of draining and preoccupying the individual, making it difficult for him or her to participate fully in family life.
Social scientists have devised a number of theories in an attempt to explain the work-family dynamic. Compensation theory is one which has been widely used. It assumes that the relationship between work and family is negative by pointing out that high involvement in one sphere- invariably the work sphere- leads to low involvement in the other. As an individual advances within a career, demands typically fluctuate from moderate to more demanding and if the advancing worker has younger children, this shift in work responsibilities will usually manifest itself in the form of less time spent with the family. Researchers subscribing to this theory point out that the drain on family time is significantly related to work-family conflict with an escalation in conflict, as the number of families increase.

The main reason fathers and mothers join the workforce is ________.

Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.

Who talks more - men or women? Most people believe that women talk more. However, linguist Deborah Tannen, who has the studied the communication style of men and women, says that this is a stereotype. According to Tannen, women are more verbal - talk more - in private situations, where they use conversation as the “glue’ to hold relationships together. But, she says, men talk more in public situations, where they use conversation to exchange information and gain status. Tannen points out that we can see these difference even in children. Little girls often play with one ‘best friend’ and their play includes a lot of conversation. Little boys often play games in groups, their play usually involves more doing than talking. In school, girls are often better at verbal skills, while boys are often better at mathematics.

A recent study at Emory University helps to shed light on the roots of this difference. Researchers studied conversation between children aged 3-6 and their parents. They found evidence that parents talk very differently to their sons than they do to their daughters. The startling conclusion was that parents use more language with their girls. Specifically, when parents talk with their daughters, they use more descriptive language and more details. There is also far more talk about emotions, especially with daughters than with sons.

Which word is similar in meaning to the word “glue” ?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to choose the word or phrase that best fits each of the numbered blanks.

Mai is my neighbor. She turned sixteen recently and her parents (46) _______ a birthday party for her. I was one of those invited. The party began at about three (47) ­­_______ the afternoon. There were about twenty of us gathering in Mai’s house. She didn’t like having the party at a restaurant (48) ­­_______ it is noisy and expensive.

We gave presents to Mai and she (49) ­­_______ opened them. It must really be exciting to receive all those presents. After that Mai’s mother served us soft drinks and biscuits. We then listened to music and played cards. The winners were given prizes. At about four-thirty, Mai’s mother brought out the birthday cake. It was beautifully decorated with pink and white icing. (50) ­­_______ colorful candles sat in the middle of the cake. We all clapped our hands eagerly and sang “Happy Birthday” as she blew out the candles and cut the cake. We helped ourselves to slices of the delicious cake and sang all the songs that we knew.

Finally, at about six in the evening, the party came to an end. We were all tired but happy. The parents of other children came to collect them by motorbikes. I helped Mai and her mother clean up the mess we had made. After that, I walked home, which was only three doors away.

Câu 48: .....................

A YEAR WITH OVERSEAS VOLUNTEERS

I was with Overseas Volunteers (OV) for a year after leaving university, and I was sent to an isolated village in Chad, about 500 km from the capital N'Djamena. Coming from' a rich country, I got quite a shock as conditions were much harder than I had expected. But after a few days I soon got used to living there. The people were always very friendly and helpful, and soon I began to appreciate how beautiful the countryside was.

One of my jobs was to supply the village with water. The well was a long walk away. And the women used to spend a long time every day carrying heavy pots backwards and forwards. So I contacted organization and arranged to have some pipes delivered. We built a simple pipeline and a pump, and it worked first time. It wasn't perfect - there were a few leaks, but it made a great difference to the villagers, who had never had running water before. And not only did we have running water, but in the evenings it was hot, because the pipe had been lying in the sun all day. All in all, I think my time with OV was a good experience. Although it was not well-paid, it was well worth doing, and I would recommend it to anyone who was considering working for a charity.

How did the author feel when he arrived in the village?

Homing pigeons are placed in a training program from about the time they are twenty-eight days of age. They are taught to enter the loft through a trap and to exercise above and around the loft, and gradually they are taken away for short distances in wicker baskets and released. They are then expected to find their way home in the shortest possible time. In their training flights or in actual races, the birds are taken to prearranged distant points and released to find their way back to their own lofts. Once the birds are liberated, their owners, who are standing by at the home lofts, anxiously watch the sky for the return of their entries. Since time is of the essence, the speed with which the birds can be induced to enter the loft trap may make the difference between gaining a win or a second place.
The head of a homing pigeon is comparatively small, but its brain is one quarter larger than that of the ordinary pigeon. The homing pigeon is very intelligent and will persevere to the point of stubbornness some have been known to fly a hundred miles off course to avoid a storm.
Some homing pigeon experts claim that this bird is gifted with a form of built-in radar that helps it find its own loft after hours of flight, for hidden under the head feathers are two very sensitive ears, while the sharp, prominent eyes can see great distances in daytime.
Why do homing pigeons fly home? They are not unique in this inherent skill: it is found in most migratory birds, in bees, ants, toads, and even turtles, which have been known to travel hundreds of miles to return to their homes. But in the animal world, the homing pigeon alone can be trusted with its freedom and trained to carry out the missions that people demand.

Why does the author mention bees, ants, toads, and turtles in the last paragraph?

Fill in each numbered blank with one suitable word or phrase

The Global Volunteer Network currently has opportunities to aim at (1) ____  primary and secondary (2) ____ to needy children, and community outreach and counseling with their partner organization in Uganda. This provides (3) _____ opportunity to experience Ugandan life first-hand (4) _____ working to improve your host community. The programs provide counseling, (5) ____ , and education for (6) ____ people, orphans and underprivileged children in small villages. The main activities will (7) ___ working with local children and youth teaching nursery, primary, and vocational education. Volunteers (8) ____ work in the areas of sport, art, games and academics. For volunteers with a medical (9) ____ and education, placements can involve work in (10) ____ clinics with small health-based community organizations.

(6) ________

Sleep is a natural process, and although a lot have been written about the subject, it is still surrounded by mystery. It is used by some as an escape from the world, and regarded by others as an irritating waste of time: some people get by on very little, others claim they cannot exist without at least ten hours, but nobody can do without sleep completely.

Our night’s sleep does not just consist of a steady phase of gradually deepening sleep. It alternates between two stages: Non-dreaming or ordinary sleep, and REM (rapid eye movement) or dreaming sleep. As soon as we fall asleep, we go straight into non-dreaming sleep for an hour or so, then into REM sleep for about 15 minutes, then back into non-dreaming sleep. It alternates in this way for the rest of the night, with non-dreaming sleep tending to last longer at the beginning of the night. Non-dreaming sleep occupies three-quarters of our night’s sleep, about a quarter of it deep and the rest fairly light. 

It is widely believed that sleep repairs the body and makes good the damage caused by being awake. However, its main function is to refresh the brain. Experts believe that probably only about two-thirds of our sleep is necessary for repairing and refreshing the brain, with the most valuable sleep coming in the first few hours of the non-dreaming period, the last few hours of sleep are not so essential. The brain can manage quite well with reduced sleep as long as it is uninterrupted sleep. 

The quality of sleep is important. A study conducted in the USA looked at short sleepers, who slept for 5.5 hours on average, and long sleepers, who had 8.5 hours or more. It is discovered after a variety of tests that the long sleepers were poor sleepers, had twice as much REM sleep as the short sleepers, appeared to sleep longer to make up for poor sleep, and did not wake up in the morning refreshed. Similarly, people who sleep deeply do not necessarily get a better quality of sleep than shallow sleepers. Deep sleepers can feel tired the following day, so six hours of good sleep is worth more than eight hours of troubled sleep.

It can be concluded from the first paragraph that ________.