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问题 填空题

用电压表可以测量某个用电器或某段电路两端的电压，

（1）测量时，电压表应该与被测用电器或电路 ______连接，

（2）连接电压表时，必须使电流从标着“+”接线柱流入，从标着“______”的接线柱流出．

（3）电压表有三个接线柱，测量时，若使用“-”和“3”两个接线柱，被测电路的电压范围是 ______；若使用“-”和“15”两个接线柱，被测电路的电压范围是 ______．

答案

（1）电压表与被测用电器并联连接，否则用电器不能正常工作；

（2）电流必须从电压表的正极流入，负极流出，否则电压表指针方向偏转；

（3）电压表有三个接线柱，所以电压表是双量程电压表，使用“-”和“3”接线柱，表示所用的量程为0～3V；使用“-”和“15“接线柱，表示所用的量程为0～15V．

故答案为：（1）并联； （2）-；（3）0～3V，0～15V．

选择题

Whether ways can be found to stop pollution or not is just _____ worries the public. [ ]

A. why

B. which

C. that

D. what

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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.

It can be inferred from the passage that the pupils ______.

A．usually study a certain subject in greater details at home than at school

B．usually do not study a certain subject at home

C．study the subjects only at school

D．study a subject more deeply at school than at home
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