激发后的原子退激时放出()
A.韧致辐射
B.湮灭辐射
C.特征X射线或产生俄歇效应
D.光电子
E.康普顿电子
参考答案:C
解析:激发后的原子退激时放出特征X射线或产生俄歇效应。
补全对话
请根据对话内容,在下面的空白处填入适当的词,使对话完整与正确,并将答案填在答题卷相应的横线上。每空一词。
Jim: What shall we do this weekend?
Li Yan: Why not 小题1: to the cinema?
Jim: That 小题2: like a good idea. I haven’t seen a film for a long time.
Li Yan: What 小题3: you like to see? The ad says there are 007 and Titanic on.
Jim: Is 007 the old one?
Li Yan: Yes, I think 小题4: . And I prefer this one. It is great.
Jim: But we have seen it before.
Li Yan: Never mind. Maybe you will like it better the second time.
Jim: OK, you win. I 小题5: James Bond(詹姆斯.邦德) very much.
Li Yan: Then we’d better hurry. It starts at 7:00 this evening.
常用联轴器有()几种。
A、齿式联轴器;
B、刚性联轴器;
C、交互式联轴器;
D、弹性栓销联轴器。