图是某区域等高（深）线示意图。读图回答题。小题1:图中所示_爱下问搜题

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问题选择题

图是某区域等高（深）线示意图。读图回答题。

小题1:图中所示河流河口附近等深线向海洋方向凸出的原因是

A．太平洋板块俯冲到亚欧板块之下形成海沟

B．滥采滥挖珊瑚礁使海水逐年变深

C．河流携带的泥沙淤积使海水逐年变浅

D．填海造陆使海水逐年变浅小题2:近几十年来这种凸向越来越大，对此应采取的根本措施是

A．禁止滥采滥挖珊瑚礁

B．做好流域内的水土保持工作

C．经常使用挖泥船清除泥沙

D．大力发展海水养殖业

答案

小题1:C

小题2:B

题目分析：

小题1:图中所示河流河口附近等深线向海洋方向凸出说明河口附近海水相对较浅，这与河流携带的泥沙淤积密切相关。

小题2:近几十年来这种凸向越来越大，说明河流含沙量大，河流含沙量大与河流中上游植被破外密切相关，因此针对河流含沙量大采取的对此应采取的根本措施是做好流域内的水土保持工作。

点评：本题难度居中，主要借助等深线的判读考查流域发展面临的问题与对策，解答本题目的关键是明确河流河口附近等深线向海洋方向凸出的原因，明确了原因知道了问题，对策就一目了然了。

单项选择题

纵隔扑动发生于（）

A.闭合性气胸

B.开放性气胸

C.张力性气胸

D.胸骨骨折

E.单纯性肋骨骨折

问答题

Man first appeared on earth about 2 million years ago. Then he was little more than an animal; but early man had a big advantage over the animals. He had in his brain special groups of nerve cells, not present in animals, that enabled him to invent a language and use it to communicate with his fellow men. 46) This ability to speak was of great value because it allowed men to share ideas, and to plan together, so that tasks impossible for a single person could be successfully undertaken by intelligent team-work. Speech also enabled ideas to be passed on from generation to generation so that the stock of human knowledge slowly increased.
It was this special ability that put men far ahead of other living creatures in the struggle for existence. 47) He mastered darkness first with dim lights and later with brighter and brighter lamps, until he can now make for himself so dazzling a light with an arc lamp that, like the sun, it is too p for his naked eyes.
48) Man found that his own muscles were too weak for the work which he wanted to do; he explored many other forms of power until now he has his hands on the ultimate source of physical energy, the nuclear power. From man’s earliest days the flight of birds has raised his wonder and desire. Why should he not fly as they did Then he began to experiment. At last he learnt how to make the right machines to carry him through the air. Now he can fly faster than sound. Already he has plans for conquering space, and a series of experiments has been completed. 49) It will not be long now before man takes a giant step away from his planet and visits the moon, learning what it is like to have no weight to his body, no upward direction and no downward.
Man, always a wanderer, has to overcome the difficulty of adapting himself to different climates. 50) Fortunately, in spite of having no thick skin or warm fur to protect him, he is peculiarly p compared with other living creatures, most of whom are unable to live far outside the region that suits them best.