根据下面的文字资料回答 71~75 题 In the following essay.each blank has four choices.Choose
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根据下面的文字资料回答 71~75 题 In the following essay.each blank has four choices.Choose the best answer and write down on the answer sheet.
Spread spectrum simply means that data is sent in( 1 )pieces over a number of the discrete frequencies available for use at any time in the specified range.Devices using( 2 ) spread spectrum(DSSS)communicate by splitting each( 3 )of data into several parts and sending them concurrently on different( 4 ),DSSS uses a lot of the available( 5 ),about 22 megahertz(MHz).
第71题:文中( 1 )处正确的答案是( )。
A.small
B.high
C.low
D.long
参考答案: