马先生2008年1月采用组合贷款法购买了住房一套，购买当月开始还款。其中40万元的公积金贷款采用等额本金贷款方式，贷款利率为5.22%，其余34万元采用等额本息的商业贷款，贷款利率为6.65%，贷款期限均为20年。

根据案例回答下列问题。

马先生公积金贷款的第一个月的还款额为（）元。

A．2501.67

B．3406.67

C．3502.91

D．4506.67

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 signal over any medium, the transmission system will limit the bandwidth that can be transmitted.

so most of the （） in this waveform is in the first few frequency components.

A．frequency

B．energy

C．amplitude

D．phase