The transmission time duration of a single pulse of radio-frequency energy is a function of the（）.

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 1/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.

The transmission of a（）indicates that a ship is in distress and requires immediate assistance.

In a design situation, there are multiple character sets that can properly encode your data. Which three should influence your choice of character set?（）

Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because （）

● Insufficient （71）can cause a processor to work at 50% or even more below itsperformance potential.（71）

In managing a situation involving multiple injuries，the rescuer must be able to（）.

CDMA for cellular system can be described as follows. As with FDMA, each cell is allocated a frequency （71） , when is split into two parts, half for reverse (mobile unit to base station) and half for （72） (base station to mobile unit). For full-duplex （73） , a mobile unit both reverse and forward channels. Transmission is in the form. of direct-sequence spread （74） , which used a chipping code to increase the data rate of the transmission, resulting is an increased signal bandwidth. Multiple access is provided by assigning （75） chipping codes to multiple users, so that the receiver can recover the transmission of an individual unit from multiple transmissions.

SCSI interfaces provide for faster data transmission rates (up to 80 megabytes per second) than standard serial and parallel ports. In addition, you can attach many devices to a single SCSI port, so that SCSI is really an I/O bus rather than simply an interface Which two statements about SCSI are true?（）

Typical MISD (multiple-instruction single-data stream) computing mode is