问题
多选题
关于电磁场和电磁波的说法正确的是[ ]
A．电磁波和机械波都能产生干涉和衍射现象
B．机械波能产生多普勒效应，而电磁波也能产生多普勒效应
C．电磁场是一种物质，不能在真空中传播
D．电磁波是纵波
答案
AB
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关于电磁场和电磁波的说法正确的是[ ]
A．电磁波和机械波都能产生干涉和衍射现象
B．机械波能产生多普勒效应，而电磁波也能产生多普勒效应
C．电磁场是一种物质，不能在真空中传播
D．电磁波是纵波
AB
| 从方框中选择恰当的选项补全对话。 | |
Jim: Hello! This is Jim. 1_______ Jane: Speaking. Jim: Hi, Jane! How are you? Jane: Fine, thanks. And you? Jim: I'm fine, too. 2_______ Jane: 3_______ Jim: Would you like to go fishing with me? Jane: 4_______ But I have something to do this afternoon. Jim: How about tomorrow afternoon? Jane: OK. 5_______ Jim: Goodbye. Jane: Bye. |