问题 单项选择题

由陨石撞击地球所形成的陨石坑在地球上虽然到处都有,但在地质较稳定的地区出现的陨石坑则最为密集。这种陨石坑的相对密集现象,肯定是由于地质较稳定地区较小的地表变化所造成的。
以下哪项是使上文结论成立的假设

A.落在同一地点的陨石,较晚落下的陨石会抹掉上一次陨石碰撞的所有痕迹。

B.任何一个地区的地表变化节奏在不同的地质时期都不相同。

C.最近,陨石在地球上的比例在不断上升。

D.在整个地球的发展史上,陨石的碰撞均匀地分布在地球表面的各个地方。

答案

参考答案:D

解析: 假设在整个地球的发展史上,陨石的碰撞均匀地分布在地球表面的各个地方,那么在地质较稳定的地区由于地衰变化较小,原来分布在这些地区地表的陨石坑受到破坏的可能性也较小。结果就形成了现在这些地区的地表的陨石坑最为密集的现象。

阅读理解

阅读理解。

     For hundreds Of years, scientists have been trying to answer what things have an effect on people's

emotions (情感). How you feel is controlled by many things. Your emotions can be affected by your

personality, by the actions of others and by events around you. Perhaps you don't know your emotions

can be influenced by the weather as well.

     People often say they feel good when the sun is shining and sad when it is cloudy. In fact, sunlight

makes us feel good. When sunlight hits our skins, our bodies produce a vitamin. Vitamins are natural

chemicals (化学物质) which we all need to stay healthy. Sunlight helps our bodies produce vitamin

D. Vitamin D helps our bodies make a special chemical. This special chemical affects our brains (大脑)

and makes us feel happy. For example, there are long, dark winters of little sunlight in Sweden and

Norway, so many people in these countries often feel sad. Without much sunlight, their bodies produce

less vitamin D. Without enough vitamin D, their bodies make less of this special chemical which makes

them feel good. To help the people in these countries feel better, special "sunrooms" with artificial (人

造的) lights have been built. People can go there and get "sunlight" for an hour or two!

     The weather can also affect people's emotions in other ways. Hot weather can make people angry

because people feel uncomfortable when they are hot. In the same way, rain can make people angry

because being wet can be unpleasant. As you can see, the weather can have an effect on the chemicals

which control our brains. Through these ways, the weather can influence our emotions. Sadly, while

the weather can change us, we can hardly change the weather.

1. Which of the following is NOT mentioned as a factor (因素) that can affect one's emotions?

A. Weather.

B. Actions of others.

C. Personality.

D. Age. 

2. Which of the following is true about vitamin D according to the passage?

A. It is a kind of artificial chemical.

B. It makes us worried by affecting our brains.

C. It is needed by us all to keep fit.

D. It is in the sunlight.

3. What can we infer (推断) from the passage?

A. We feel good when we are in the bright cool weather.

B. We will be happy when we are caught in the rain.

C. All people in Norway and Sweden feel sad in winter.

D. The more vitamin D you have, the happier you'll be.

4. What may be the best title for this passage?

A. Why Do We Feel Sad?

B. The Weather Influences People's Emotions

C. People Need More Vitamin D

D. We Can Hardly Change the Weather

辨析题