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问题 填空题

幻灯机的镜头相当于一个______镜，用强光照射幻灯片，幻灯片上的画面在屏幕上形成______像（填“虚”或“实”）

答案

幻灯机是根据凸透镜成倒立、放大的实像工作的，幻灯机的镜头相当于一个凸透镜．

故答案为：凸透；实．

听力题

根据句意及所给的汉语，补全所缺的单词，每空限填一词。

小题1:The girl often helps me with my __________（最糟糕的）subject.

小题2:I think you made a good _________（决定）.

小题3:We looked at each other in _________（沉默）.

小题4:I had an unusual           (经历) last Sunday.

小题5:You shouldn’t _________ (播放) your CDs too loudly.

小题6:Now many students are under too much __________（压力）.

小题7:If Paul _________（失败）the exam again, his teacher will talk with his parents about it.

小题8:He had an accident. But ___________（幸运地）, he was not badly hurt.

小题9:It is very __________（危险的）to play football in the street.

小题10:He didn’t know what was __________（发生）outside.
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单项选择题

在以太网中的任何结点发送数据______。

A．都是随机的

B．都需要预约发送时间

C．都是定时的，即按固定时间片发送

D．需通过一个公式计算时间
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