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问题 填空题

如何用所提供的试剂和方法除去各粉末状混合物中的杂质(括号内为杂质)。将所选答案的编号填入在表内相应的空格内(如果不需要外加试剂，则对应答案栏可空着)。

可供选择的试剂：A.盐酸　B．氢氧化钠溶液　C．氧气　D．水　E．二氧化碳

可选用的操作：①水洗　②加热　③高温灼烧　④过滤　⑤结晶

答案

（1）B 、④

（2）D、④⑤

（3）A、④

（4）A、④

（5）—、③

（6）—、②

听力题

66. We have to get the job done ____________(秘密地). We don't want others to know about it.

67. My train was 20 minutes late in the morning and there was a ___________(相似的)delay in the evening. 

68.Miss Li speaks English with excellent _______________(语音). 

69. This company is one of the Post Office's biggest _____________(顾客.客户).

70. The drowning swimmer required the lifeguard's _______________(即刻的)attention.

71. Our victory was ________________(庆祝) with music and dancing.

72. I've never seen a Shakespeare's play ______________(表演) so wonderfully.

73. Nowadays most people use paper _________________(手帕) .

74. The boy spoke in a very low voice , ___________(承认) he had broken the glass.

75.The_______________(大多数)of people in my neighborhood are Italian.
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单项选择题

（）如果机组运行中风速仪发生结冰情况，会出现如下那种现象.

A.机组故障停机

B.风机报风速仪故障

C.功率大风速小正常运行

D.功率小风速小正常运行
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