问题 不定项选择

有一种测量体重的电子秤,如图示意,它由三部分构成:踏板、压力传感器R(阻值随所受压力大小发生变化的电阻),显示体重大小的仪表G(实质是理想电流表),设踏板的质量可忽略,已知电流表的量程为3A,电源电动势为12V,内阻为2Ω,电阻随压力变化的函数式为R=30-0.02F(F和R的单位分别是N和Ω),下列判断正确的是

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A.该秤测量的最大体重是1400N

B.该秤测量的最大体重是1300N

C.该秤的零刻线(踏板空载的刻线)应在G刻度盘0.375A处

D.该秤的零刻线(踏板空载的刻线)应在G刻度盘0.400A处

答案

AC

综合题
阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项.选项中有两项为多余选项.

We are all called upon to make a speech at some point in life, but most of us don’t do a very good job.  1  

So, you have to give a speech and you are terrified. You get nervous, you forget what you want to say, you stumble over words, you talk too long, and you bore your audience. Later you think, “Thank Goodness, it’s over. I’m just not good at public speaking. I hope I never have to do that again.”

Cheer up!  2  Here are some simple steps to take the pain out of speech making. Ask yourself the purpose of your speech. What is the occasion? Why are you speaking? Then, gather as many facts as you can on your subject. Spend plenty of your time doing your research. Then spend plenty of your time organizing your material so that your speech is clear and easy to follow. Use as many examples as possible, and use pictures, charts, and graphs if they help you make your points more clearly.   3  Don’t talk over their heads, and don’t talk down to them. Treat your audience with respect. They will appreciate your thoughtfulness.

Just remember: Be prepared. Know your subject, your audience, and the occasion. Be brief.  4  And be yourself. Let your personality come through so that you make person-to-person contact with your audience.

If you follow these simple steps, you will see that you don’t have to be afraid of public speaking. In fact, you may find the experience so enjoyable that you volunteer to make more speeches! You’re not convinced yet?   5  

A.It doesn’t to be that bad.

B.Take several deep breaths before your speech.

C.This article gives some advice on how to give good speech.

D.Say what you have to say and then stop.E. Don’t say what you aren’t familiar with.

F. Never forget your audience.

G. Give it a try and see what happens.