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问题 选择题

选择坝址是建筑水库的关键之一，除地形等其他因素外，下列四种地质构造中最适宜于建坝的是

答案

答案：D

本题分别画了四个地质构造，A.B两图为断层，C图为背斜，D图为向斜。三种地质构造中，对修建水库大坝最不利的是有断层的地方。C中大坝建在背斜的顶部，背斜顶部因受张力，岩层破碎，岩基不稳定，也不宜建大坝，而D图中大坝建在向斜的槽部，向斜槽部受到挤压力，物质坚实不易被破坏，所以建大坝较为稳定。

单项选择题

污水处理中生化处理阶段一般设有（）

A.曝气池

B.二次沉淀池

C.包含A和B

D.不包含A和B
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单项选择题

Children are a relatively modem invention. Until a few hundred years ago they look like adult, wearing grown-up clothes and grown-up expressions, performing grown-up tasks. Children did not exist because the family as we know it had not evolved.
Children today not only exist; they have taken over in no place more than in America, and at no time more than now. It is always Kids Country here. Our civilization is child-centered, child-obsessed. A kid’s body is our physical ideal. In Kids Country we do not permit middle-aged. Thirty is promoted over 50, but 30 knows that soon his time to be overtaken will come.
We are the first society in which parents expect to learn from their children. Such a topsy-turvy situation has come to abort at least in part because, unlike the rest of the world, ours is an immigrant society, and for immigrants the only hope is in the kids. In the Old Country, that is, Europe, hope was in the father, and how much wealth he could accumulate and pass along to his children. In the growth pattern of America and its ever- expanding frontier, the young man was ever advised to GO WEST; the father was ever inheriting from his son. Kids Country may be the inevitable result.
Kids Country is not at all bad. America is the greatest country in the world to grow up in because it is Kids Country. We not only wear kids clothes and eat kids food; we dream kids dreams and make them come tree. It was, after all, a boys’ game to go to the moon.
If in the old days children did not exist, it seems equally true today that adults, as a class, have begun to disappear, condemning all of us to remain boys and girls forever, jogging and doing push-ups against eternity.

Which of the following sentences is the main idea of this passage

A．Children in the Old Country are not as happy as their counterparts in America.
B．America is a country in which the concept of children is more emphasized than any other countries in the world.
C．Adults in America are becoming increasingly useless.
D．Adults should learn from their children because they are more energetic.
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