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问题 选择题

下列对检验方法或现象描述不正确的是（  ）

A．乙烷中是否混有乙烯，可用通过溴水是否褪色进行检验

B．乙醇中是否混有水，可用加硫酸铜粉末是否变蓝进行检验

C．乙酸中是否混有乙醇，可用加入金属钠是否产生气体进行检验

D．乙酸乙酯是否混有乙酸，可用加石蕊试液是否变红进行检测

答案

答案：C

C项，乙酸和乙醇，都能与金属钠反应产生氢气，因此不能用金属钠检验乙酸中是否混有乙醇。

判断题

等密度线制图不能采用绝对值，如要表示区域单元的数值，必须将绝对数值转为单位面积的比率或比值。
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填空题

The other day my brother Tom was beginning his 56.______
motorbike then our neighbor, Mary came out and asked 57.______
him if he was going near the station. So he offered her a lift.
She got at the back of the motorbike and 58.______
they drove away. Just before they reached to the station 59.______
a policeman waved to them to stop. "Excuse me, sir," he said,
"You are not sitting on that motorbike properly. "
"What’s matter with the way I’m sitting" my brother 60.______
asked in surprise. "Not you sir. It’s a young lady," said 61.______
the policeman, "In this country side-saddle(偏座) is not62.______
permitted when one ride a motorbike．”Mary made an excuse 63．______
that she was from Italy，where it isn’t．considering to 64．______
break the law when people take the side-saddle．
The policeman shook head and drove away． 65.______
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