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问题 单项选择题

我国的政府预算由( )组成。

A．中央和地方两级预算

B．中央、省、市三级预算

C．中央、省、市、县四级预算

D．中央、省，市，县、乡五级预算

答案

参考答案：D

解析： 此题与2003年单选21题完全相同，即此处为考试重点。

选择题

----Please come in and make yourself___________.

----- Thank you ！

A．at sea

B．at will

C．at home

D．at sight
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单项选择题

Although a given waveform may contain frequencies over a very broad range, as a practical matter any transmission system will be able to accommodate only a limited band of （1）. This, in turn, limits the data rate that can be carried on the transmission （2）. A square wave has an infinite number of frequency components and hence an infinite （3）. However, the peak amplitude of the kth frequency component, kf, is only l/k, so most of the （4） in this waveform is in the first few frequency components. In general, any digital waveform will have（5） bandwidth. If we attempt to transmit this waveform as a signal over any medium, the transmission system will limit the bandwidth that can be transmitted.

（5）是（）

A.small

B.limited

C.infinite

D.finite
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