Earth is richly supplied with different types of living organisms which co-exist in their environments, forming complex, interrelated communities. Living organisms depend on one another for nutrients, shelter, and other benefits. The extinction of one species can set off a chain reaction that affects many other species, particularly if the loss occurs near the bottom of the food chain. For example, the extinction of a particular insect or plant might seem inconsequential. However, there may be fish or small animals that depend on that resource for foodstuffs. The loss can threaten the survival of these creatures and larger predators that prey upon them. Extinction can have a ripple effect that spreads throughout nature.

   In addition to its biological consequences, extinction poses a moral dilemma for humans, the only species capable of saving the others. The presence of humans on the planet has affected all other life forms, particularly plants and animals. Human lifestyles have proven to be incompatible with the survival of some other species. Purposeful efforts have been made to eliminate animals that prey on people, livestock, crops, or pose any threat to human livelihoods. Some wild animals have been decimated by human desire for meat, hides, fur, or other body parts with commercial value. Likewise, demand for land, water, and other natural resources has left many wild plants and animals with little to no suitable habitat. Humans have also affected nature by introducing non-native species to local areas and producing pollutants having a negative impact on the environment. The combination of these human-related effects and natural obstacles such as disease or low birthrates has proven to be too much for some species to overcome. They have no chance of survival without human help.

   As a result, societies have difficult choices to make about the amount of effort and money they are willing to spend to save imperiled species. Will people accept limits on their property rights, recreational activities, and means of livelihood to save a plant or an animal? Should saving such popular species as whales and dolphins take priority over saving obscure, annoying, or fearful species? Is it the responsibility of humans to save every kind of life form from disappearing, or is extinction an inevitable part of nature, in which the strong survive and the weak perish? These are some difficult questions that people face as they ponder the fate of other species living on this planet.

The word "They" in paragraph 2 refers to ______.

Câu hỏi liên quan

• What happened to make Bethan decide to quit Facebook for a while?

• According to the passage, travel books, biographies and memoirs ______.

• The word “vacations” in line 9 could be best replaced by ..............

ZUNIA12

• Which of the following conclusions about squirrels is supported by information in the passage?

• The word "fused" in line 2 is closest in meaning to .........

• What does this paragraph mainly discuss?

• What does the passage mainly discuss?

• According to the passage Moore wrote about all of the following EXCEPT ________

• The expression “is based on” in the first paragraph could be best replaced by ..............

• In the passage, the author’s attitude towards “mixed-ability teaching” is_____.

• The word “their” in line 1 refers to ...........

• The word "rude" is closest in meaning to ............

• The word “disparage” in the passage mostly means ........

• A patient can still live a comfortable life even after the removal of ..........

• The word “this” as used in paragraph 2 refers to ___________.

• The writer's father retired early because ..................

• What is the main idea of the passage?

• According to the passage, the Railway Mail Service commenced in ......

• Which of the followings is NOT an evidence of monitoring studying?

• The word “vary” in paragraph 6 can be best replaced by ___________.