补出下列文中空缺的部分。

11、唯江上之清风，与山间之明月，___________________，目遇之而成色，_____________，用之不竭，是造物者之无尽藏也，而吾与子之共适。(苏轼《赤壁赋》)

12、且夫天地之间，物各有主＿＿＿＿＿＿＿＿＿，＿＿＿＿＿＿＿＿（苏轼《赤壁赋》）

13、物华天宝，_________________________；人杰地灵，________________。(王勃《滕王阁序》)

14、十旬休假，胜友如云；_____________,______________。腾蛟起凤，孟学士之词宗；_________________,_____________________。(王勃《滕王阁序》)

15、 ________________,____________________。渔舟唱晚，响穷彭蠡之滨；______________,_________________。(王勃《滕王阁序》)

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 (86) . This, in turn, limits the data rate that can be carried on the transmission (87) A square wave has an infinite number of frequency components and hence an infinite (88) However, the peak amplitude of the kth frequency component, kf, is only l/k, so most of the (89) in this waveform is in the first few frequency components. In general, any digital waveform will have (90) 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.

（88）是（）

A.source

B.bandwidth

C.energy

D.cost