- 精华
- 0
- 积分
- 297
- 经验
- 297 点
- 威望
- 0 点
- 金钱
- 480 ¥
- 魅力
- 327
|
今天做了test8,其中19,20两题我的思路怎么也理不清,求助!Questions 19-20
Oxygen.18 is a heavier-than-normal isotope of oxygen. In a rain cloud, water molecules containing oxygen-18 are rarer than water molecules containing normal oxygen. But in rainfall, a higher proportion of all water molecules containing oxygen-18 than of all water molecules containing ordinary oxygen descends to earth. Consequently, scientists were surprised when measurements along the entire route of rain clouds' passage from above the Atlantic Ocean, the site of their original formation, across the Amazon forests, where it rains almost daily, showed that the oxygen-18 content of each of the clouds remained fairly constant.
19. Which one of the following statements, if true, best helps to resolve the conflict between scientists' expectations, based on the known behavior of oxygen-18, and the result of their measurements of the rain clouds' oxygen-IS content?
(A) Rain clouds above tropical forests are poorer in oxygen-18 than rain clouds above unforested regions.
(B) Like the oceans, tropical rain forests can create or replenish rain clouds in the atmosphere above them.
(C) The amount of rainfall over the Amazon rain forests is exactly the same as the amount of rain originally collected in the clouds formed above the Atlantic Ocean.
(D) The amount of rain recycled back into the atmosphere from the leaves of forest vegetation is exactly the same as the amount of ram in river runoffs that is not recycled into the atmosphere.
(E) Oxygen-18 is not a good indicator of the effect of tropical rain forests on the atmosphere above them.
20. Which one of the following inferences about an individual rain cloud is supported by the passage?
(A) Once it is formed Over the Atlantic, the rain cloud contains more ordinary oxygen than oxygen-18.
(B) Once it has passed over the Amazon, the rain cloud contains a greater-than-normal percentage of oxygen-18.
(C) The clouds rainfall contains more oxygen-18 than ordinary oxygen.
(D) During a rainfall, the cloud must surrender the same percentage of its ordinary oxygen as of its oxygen-18.
(E) During a rainfall, the cloud must surrender more of its oxygen-l8 than it retains.
另外第10题更让我一头雾水,不知道在扯什么?
10. Most people are indignant at the suggestion that they are not reliable authorities about their real wants. Such self-knowledge, however, is not the easiest kind of knowledge to acquire. Indeed, acquiring it often requires hard and even potentially risky work. To avoid such effort, people unconsciously convince themselves that they want what society says they should want.
The main point of the argument is that
(A) Acquiring self-knowledge can be risky
(B) Knowledge of what one really wants is not as desirable as it is usually thought to be
(C) People cannot really want what they should want
(D) People usually avoid making difficult decisions
(E) People are not necessarily reliable authorities about What they really want
谢谢! |
|