题干

某学生用电流表和电压表测干电池的电动势和内阻时,所用滑动变阻器的阻值范围为0~20 Ω,连接电路的实物图如图所示。关于该学生接线的说法正确的是(  )

A:滑动变阻器不起变阻作用  

B:电流表接线有误

C:电压表量程选用不当

D:电压表接线不妥

上一题 下一题 0.0难度 选择题 更新时间:2018-03-08 11:02:26

答案(点此获取答案解析)

A,B,D

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任务型阅读

    One morning last week I looked out of my study window and saw that it was a fine day. No, it was a wonderful day: the sun shone down from a sky without even a single cloud. But later that day, hard at work at my desk, I heard a loud noise on the roof. Turning to the window, I saw that the sky was now the color of charcoal. Two minutes later the rain poured, making rivers of water.

    ____It's extremely variable. Go ahead with your picnic in the local park by all means, but don't suppose that because the sun is shining now, it will be when you open your pack of sandwiches.  ____

    The weather in Britain is not always bad.____This is one of the biggest reasons why the British talk so often about the weather. Wherever there are strangers standing or sitting close together, and talk can not be avoided. The conversation focuses on the weather: “Yes, the weather has been good, hasn't it?” or “____

    The unexpected change of the weather is something that every British can agree on.____ Even those with different opinions on everything else in the world, such as the argument in the UK about membership of the European Union, can talk about the weather without leading to a quarrel.

A. It is just changeable.

B. That makes it a safe topic of conversation.

C. You'd better take an umbrella, just in case.

D. What shocking weather we've been having!

E. Strangers will choose to talk about the weather to break the ice.

F. This story will give you some idea about weather in Britain.

G. Are you going for a picnic?