制20节底面半径为5厘米、长为40厘米的圆柱形铁皮通风管，至少要_爱下问搜题

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问题解答题

制20节底面半径为5厘米、长为40厘米的圆柱形铁皮通风管，至少要用多大面积的铁皮？

答案

（3.14×5×2×40）×20，

=（3.14×400）×20，

=3.14×8000，

=25120（平方厘米）；

答：至少要用25120平方厘米的铁皮．

完形填空

My husband hasn’t stopped laughing about the thing that happened to me. It’s 26  now but it wasn’t that time.
Last Friday, after doing all the family shopping in town, I 27 a rest before catching the train, so I bought a   28 and some chocolate and went to the station coffee shop that was a cheap, self-service place with long   29 to sit at. I put my heavy bag down on the floor, put the newspaper and chocolate on the table to   30 a place and went to get a cup of coffee.
When I came back with the coffee, there was someone in the   31   seat. It was one of those   32 young man, with dark glasses and torn clothes, and hair colored bright 33  at the front, not so unusual these days. What did 34 me was he’d started to eat my chocolate! Naturally, I was annoyed. However, to avoid trouble—then really I was rather uneasy about him—I just   35 down at the front page of the newspaper, tasted my coffee, and took a bit of chocolate. The boy looked at me    36   . then he took another piece of my chocolate. I could hardly   37 it. Still I didn’t want to start an argument. When he took a  38    piece , I felt more 39 than annoyed. I thought, “ Well, I shall have the last piece.” And I 40 it.
The boy gave me a   41  look, and then stood up. As he left, he shouted out, “This woman is mad!” Everyone   42 . That really made me feel silly, but it was   43   when I finished my coffee and got ready to leave. My face went red—as red as his hair when I   44    I’d made a mistake. It wasn’t my chocolate he’d been taking. There was mine, unopened, just under my 45   .

A．wild-looked

B．wild-looking

C．good-looking

D．good-looked

单项选择题

当船舶重心在稳心上时称船舶处于（）状态。

A．稳定平衡

B．不稳定平衡

C．随遇平衡

D．中性平衡