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问题 问答题 简答题

用一根直径为26毫米，强度极限为1519N/平方毫米的6*37钢丝绳作捆绑吊索，求此吊索的允许拉力。（破断拉力总和为380730N，安全系数取8，换算系数取0.82）。

答案

参考答案：允许拉力=（380730*0.82）/8=39024.8N

即此钢丝绳吊起的重物不能超过39024。8N。

听力题

阅读下面材料，在空白处填入适当的内容（不多于3个单词）或括号内单词的正确形式。

We high school students do have some growing pains, but we can get rid of them__小题1:__ (correct) and wisely. __小题2:__, some of us are upset __小题3:__ our body styles and looks. It’s unnecessary and it’s not important at all. We needn’t care about it. It is one’s inner beauty __小题4:__ matters. Second, we sometimes seem to be misunderstood by our teachers, parents and classmates. __小题5:__ (face) with this, we can find a proper time to have a heart-to-heart talk with them, trying __小题6:__ (remove) the misunderstanding. Some of us have fewer friends. I think being open-minded and friendly will do you good. Third, we may fall behind others, __小题7:__ makes us stressed. Actually we can encourage __小题8:__ to work efficiently, full of __小题9:__ (determine). At last, some of us don’t have much pocket money, so they feel unhappy. Isn’t it strange? So long as we have some, that’s enough. And we can learn__小题10:__ to spend money.
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单项选择题

熟悉这些种属差别有利于选择实验动物和分析实验结果。如大小鼠（）呕吐反应。

A.有敏感的

B.有不敏感度

C.无

D.大多有
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