选择题：Although a given waveform may contain frequencies over a very broad range， as a

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（　　）.This， in turn，limits the data rate that can be carried on the transmission（　　）. A square wave has an infinite number of frequency components and hence an infinite（　　）.However， the peak amplitude of the kth frequency component， kf， is only 1/k， so most of the（　　）in this waveform is in the first few frequency components. In general， any digital waveform will have（　　）bandwidth. If we attempt to transmit this waveform as a signalover any medium， the transmission system will limit the bandwidth that can be transmitted.
问题1选项
A.frequencies
B.connections
C.diagrams
D.resources
问题2选项
A.procedures
B.function
C.route
D.medium
问题3选项
A.source
B.bandwidth
C.energy
D.cost
问题4选项
A.frequency
B.energy
C.amplitude
D.phase
问题5选项
A.small
B.limited
C.infinite
D.finite