OTDR（Optical Time Domain Reflectometer，光时域反射仪）的主要作用包括（）。
第1题：
A. low optical power
B. high optical power
C. few optical channels
D. many optical channels
E. low chromatic dispersion
F. high chromatic dispersion
G. too much power differential in the optical channels
第2题：
A large corporation is concerned about the amount of time it takes to back up their main file server. They are also concerned that their IT technician frequently forgets to change the backup tapes， thereby leaving the company open to data loss. Which backup system would solve both problems？（）
第3题：
一个RB由若干个RE组成，频域宽度为『____』kHz，时间长度为『____』ms。(A RB is composed of several RE , and it's width is『____』kHz in the frequency domain , the length is『____』ms in the time domain. )
第4题：
display interface pos命令输出信息Rx Optical Power、Tx Optical Power表示（）。
第5题：
A corrupted file system is now repaired and back in use. Some， but not all of the files within the file systems have been deleted. The only backup of this file system is a month-old tar archive. This archive will need to be restored as root. Which two statements correctly describe the effects of the restore operation？（）
第6题：
What three in combination are factors that can cause four-wave mixing in fiber-optic cables? （）(Choose three.)
第7题：
Which two statements are true about optical networks?（）
第8题：
A.NTP
B.FTP
C.RTP
D.IGMP
第9题：
When deployed to transmission application of wavelengths up to 160 wavelengths, the ZXWM M900 performs optical amplification of signals at the C band and the L band independently at the same time.
第10题：
OWM的英文全称是（）