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问题 填空题

如果电缆调制解调器使用4MHz的频带宽度，那么，在利用256QAM时，它可以提供的速率为　【20】　Mbps。

答案

参考答案：32

解析：

【解析】可提供的最大速率=Log2256/Log22(bit/Hz/s)×4MHz=32MHz

阅读理解

Dave Smith is 12. He has a sister .Her name is Jenny .She is 8.

Dave has a dictionary .It is blue .The dictionary is in his black backpack .He has a computer game and he likes it .Jenny has a watch .It is red .She likes it very much. She has a good pencil case ,too .It’s white . Her pencil  ,ruler ,eraser and pen are in the pencil case. Her pencil case is in her yellow backpack.

小题1:What’s Jenny’s family name?

A．White

B．Black

C．Smith

D．Brown小题2:What color is Dave’s dictionary?

A．It’s blue.

B．It’s black.

C．It’s red.

D．It’s white.小题3:_________ things are in Jenny’s pencil case.

A．One

B．Two

C．Three

D．Four小题4:What color is Jenny’s backpack?

A．It’s black

B．It’s red

C．It’s green

D．It’s yellow小题5: 下面哪项陈述是正确的？

A．Dave is 8

B．Jenny has a computer game

C．Dave’s backpack is black

D．Jenny has a sister
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单项选择题

日本教育家铃木镇一创立了（）教学法。

A.体态律动

B.才能教育

C.奥尔夫

D.综合音乐
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