题目内容
【题目】 下列属于我国地势第一、第二级阶梯分界线的是（ ）
A.大兴安岭—太行山脉—巫山—雪峰山 B.昆仑山脉—祁连山脉—横断山脉
C.天山山脉—阴山山脉—燕山山脉 D.长白山脉—武夷山
【答案】B
【解析】
试题分析：
我国地势西高东低，呈三级阶梯分布。其中昆仑山脉、祁连山脉、横断山脉一线是地势第一阶梯和第二阶梯的分界山脉，大兴安岭、太行山、巫山、雪峰山一线是地势第二阶梯和第三阶梯的分界山脉，故本题选B。
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【题目】（题文）
We all know the strange feeling of watching the time change on a o’clock.
You never really see it change because the hands move so slowly. But, of course, the time is changing all the time.
Human faces, like clock faces, are also changing. And like clocks, the changes take place too slowly to be noticed. Over many thousands of years, though, huge changes are possible. For example, the human brain tripled (三倍的) in size. Our faces became flatter, and we began to think more.
If our heads became larger in the past, how will things change in the future? Unlike the changes of a clock face, the changes in human faces are not easy to predict (预测). It is mainly because of the way in which we can now control parts of nature. Hundreds of thousands of years ago, all changes were natural, but now we can actively choose paths for our own evolution(进化).
A US artist named Nickolay Lamm has recently offered an idea at what human faces may one day look like. The designs, inspired (受启发) by his conversations with scientist Alan Kwan, show humans with larger heads and eyes. In particular, Lamm predicts the forehead may be larger because of increasing usage of the brain.
Just a few hundred years ago, most humans were working in the fields, while nowadays more and more people get education. These are just predictions, and no one can be sure how human beings will evolve(进化) in the future. But with such huge changes in our environment, it seems likely that we will look very different one day.
Changes to human faces | |
Similarity between the changes to the（小题1） and ones to human faces | They both keep changing all the time. But these changes are too （小题2） to be noticed. Over the time, it is （小题3） for huge changes to take place. |
（小题4） of human faces changes in the past | The human （小题5） is three times as large as it was thousands of years ago. Human faces became flatter and humans began to think more. |
Possible changes in the （小题6） | It is hard to predict. One of the main（小题7） can be the way in which humans can control parts of the nature. A US（小题8）, Lamn, shows humans with larger heads and eyes. Lamn predicts that because humans（小题9） the brain more often, the forehead may be larger. |
Conclusion | How human beings will evolve is （小题10） . But the huge changes in our environment are likely to make humans look very different. |
