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问题 单项选择题

孔隙率、空隙率、含水率和吸水率等是建筑材料的一些基本物理参数。下列对这些参数的表述，正确的是（）。

A．孔隙率：材料中孔隙体积与实体部分体积之比

B．空隙率：材料中直径在0.5—5mm以上的空隙与材料总体积之比

C．含水率：材料内部所含水分体积与材料总体积之比

D．吸水率：材料由干燥状态达到饱和吸水状态时增加的质量与材料干质量之比

答案

参考答案：B

解析：A项应为孔隙率为材料中孔隙体积与总体积之比；C项应为含水率是指材料在空气中吸入水的质量与干燥材料质量的比；D项应为吸水率是指材料在吸水饱和状态下，吸入水的质量与干燥材料质量之比或吸入水的体积与材料在自然状态下的体积之比。只有B项表述无误，故选之。

单项选择题

为验证某个程序模块能否与其他模块按照规定方式正确工作，需要进行（）。

A．单元测试

B．组装测试

C．系统测试

D．确认测试
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单项选择题

Of all the areas of learning the most important is the development of attitudes. Emotional reactions as well as logical thought processes affect the behavior of most people.
"The burnt child fears the fire" is one instance ; another is the rise of despots like Hitler. Both examples also point up the fact that attitudes stem from experience. In one case the experience was direct and impressive; in the other it was indirect and cumulative. The Nazis were indoctrinated largely by the speeches they heard and the books they read.
The classroom teacher in the elementary school is in a strategic position to influence attitudes. This is true partly because children acquire attitudes from those adults whose word they respect.
Another reason it is true is that pupils often delve somewhat deeply into a subject in school that has only been touched upon at home or has possibly never occurred to them before. To a child who had previously acquired little knowledge of Mexico, his teacher’s method of handling such a unit would greatly affect his attitude toward Mexicans.
The media through which the teacher can develop wholesome attitudes are innumerable. Social studies (with special reference to races, creeds and nationalities) , science matters of health and safety, the very atmosphere of the classroom... these are a few of the fertile fields for the inculcation of proper emotional reactions.
However. when children come to school with undesirable attitudes, it is unwise for the teacher to attempt to change their feelings by cajoling or scolding them. She can achieve the proper effect by helping them obtain constructive experiences.
To illustrate, first grade pupils afraid of policemen will probably alter their attitudes after a classroom chat with the neighborhood officer in which he explains how he protects them. In the same way, a class of older children can develop attitudes through discussion, research, outside reading and all-day trips.
Finally, a teacher must constantly evaluate her own attitudes, because her influence can be deleterious if she has personal prejudices. This is especially true in respect to controversial issues and questions on which children should be encouraged to reach their own decisions as a result of objective analysis of all the facts.

The author of this passage tries to ______.

A．present certain facts of how the development of a person’s attitude can be influenced

B．show that our society is not doing enough to help children shape their attitudes

C．point out that teachers are the only people who can influence the children’s attitudes

D．prove that speeches and books are the only factors to indoctrinate children
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