21. Leona: If the average consumption of eggs in the United States were cut in half, an estimated 5,000 lives might be saved each year. Thomas: How can that be? That would mean that if people adopt this single change in diet for ten years, the population ten years from now will be greater by 50,000 people than it otherwise would have been. Which one of the following is a statement that Leona could offer Thomas to clarify her own claim and to address the point he has made? (A) It is possible for the population to grow by 5,000 people for every year if the base year chosen for purposes of comparison is one with unusually low population growth. (B) It is accurate to say that 5,000 lives have been saved as long as 5,000 people who would have died in a given year as a result of not changing their diet, did not do so-even if they died for some other reason. (C) If egg consumption were reduced by more than half, the estimated number of lives saved each year could be even more than 5,000. (D) The actual rate of population growth depends not only on the birth rate, but also on changes in life expectancy.(B) (E) For the average consumption of eggs to be cut by half, many individual consumers would have to cut their own consumption by much more than half.
不是很明白~能不能有前辈指点一下呢?谢谢哦~~~ |