如图所示的电路中,电源电动势为E,内电阻为r,平行板电容器C的两金属板水平放置,

题型:不定项选择

问题:

如图所示的电路中,电源电动势为E,内电阻为r,平行板电容器C的两金属板水平放置,R1和R2为定值电阻,P为滑动变阻器R的滑动触头,G为灵敏电流计,A为理想电流表。开关S闭合后,C的两板间恰好有一质量为m、电荷量为q的油滴处于静止状态,则以下说法正确的是

[ ]

A.在P向上移动的过程中,A表的示数变大,油滴仍然静止,G中有方向由a至b的电流

B.在P向上移动的过程中,A表的示数变小,油滴向上加速运动,G中有方向由b至a的电流

C.在P向下移动的过程中,A表的示数变大,油滴向下加速运动,G中有由a至b的电流

D.在P向下移动的过程中,A表的示数变小,油滴向下加速运动,G中有由b至a的电流

考点:闭合电路欧姆定律
题型:不定项选择

三、阅读(共两节,满分40分)

第一节:阅读下面短文,从每题所给的A、B、C、D四个选项中,选出最佳选项,并把答案写在答题卷上。(共15小题,每小题2分,满分30分)

A

Some people have the feeling that nothing can be done about their poor reading ability. They feel hopeless about it. Can you learn to read better, or must you agree that nothing can be done about it?

To be sure, people are different. You cannot expect to do everything as well as certain other people

do. If all the students in a class tried out for basketball, some would be very good players; others would be very poor; and many would be in between. But even the very poor players can become much better players if they are guided in the right way, and with plenty of practice. It is the same with reading. Some seem to enjoy reading and to read well without any special help. Others find reading a slow and tiring job. In between, there are all degrees of reading ability.

Many experiments have shown that just about every poor reader can improve his reading ability. In these experiments, the poor readers were given tests of reading ability. After some of the causes of their reading were discovered, they were given special instruction and practice in reading. After a few months, another test of the same kind was given. In nearly all cases, these people had raised their reading scores.

41.   With the example of basketball players, the author shows ________.

A. why certain people are poor readers        B. that there are differences in people’s abilities

C. why some people are good basketball players

D. that good basketball players can be good readers

42.   To improve their reading ability, people should ________.

A. work long and hard                               B. take different forms of tests

C. have special help and practice                 D. try different reading materials

43.   The experiments mentioned in the text show that ________.

A. good readers seem to enjoy reading        

B. almost all poor readers can make progress

C. causes of poor reading were difficult to find out

D. tests help people improve their reading ability

44.   What does the underlined sentence “many would be in between” mean?

A. It means that many are the best basket players.

B. It means that many are the worst basket players.

C. It means that many are standing in the middle of the line.

D. It means that there are several levels of players in many students.

45.   What’s the purpose of the author’s writing this passage?

A. To encourage people to improve their reading ability.

B. To suggest that readers should do practice only in reading.

C. To tell us that readers can’t improve their reading ability without special help.

D. To tell us that to be a good reader, one should be guided in the right way.

题型:不定项选择

黄金市场的交易方式有现货交易和期货交易两种。()

题型:不定项选择

变形缝是为防止建筑物在外界因素(温度变化、地基不均匀沉降及地震)作用下产生变形,导致开裂甚至破坏而认为设置的适当宽度的缝隙。

题型:不定项选择

为了减小地震作用,应尽量减轻建筑物自重并降低重心位置,可将设备层或大型设备布置在建筑物的地下室、底层或下部几层。

题型:不定项选择

铁路信息系统运行维护工作包括哪些?

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