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问题 单项选择题

异烟肼的鉴别试验是

A．银镜反应
B．加硫酸、硝酸等氧化剂后呈现红色
C．溶于硫酸后，在365nm紫外光下呈黄绿色荧光
D．水解后的重氮化-偶合反应
E．铜吡啶反应

答案

参考答案：A

完形填空

根据短文内容和首字母提示，在下文空格处填入适当的词使短文完整。(每空一词)

Books bring us k____小题1:____ which enriches (丰富)our lives and b___小题2:___ us happiness.

All great men in the history of mankind(人类) l____小题3:____ books. There is no genius(天才) without books. We know that books are treasure of knowledge, and knowledge is power. Without it, we can achieve(取得) n___小题4:___. A man is blind and does not even know w____小题5:___he is doing if he is unable to read.

Books bring us h____小题6:___ as well as knowledge. They enable us not only to see through the past, but also to see into the f___小题7:_____.

Macaulay, a famous historian of England, once wrote to a little girl, “ If anyone would make me the greatest king that ever lived with palaces, fine dinners , wines, b____小题8:____ clothes and hundreds of servants, on condition that I should not read books, I would not be the king. I would rather be a p____小题9:____ man with a lot of books than a king w____小题10:___ any books in his splendid palace.
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多项选择题

使用水介质液力偶合器时，偶合器应具备（）保护。

A.木楔

B.易熔塞

C.易爆塞

D.保险丝
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