Which of the following cables would a technician make in order to identify a physical interfaceproblem?（）
A、Serial
B、Loopback
C、Rollover
D、Console
Which of the following commands will only provide a snapshot of average memory usage for a process？（）
A、 vmtune
B、 ps au
C、 iostat
D、 rmss -m
为了与具体的物理传输介质无关，TCP/IP结构中并没有对最低两层做出规定。
A、对
B、错
驻波比是用来表示（）和电波发射台是否匹配的参数。
A、信号
B、增益
C、天线
D、功率
通常所说的天线绝对高度指的是天线的挂高加上天线所在铁塔海拔与覆盖区域的差值。
A、对
B、错
An administrator is ordering a new Power 550. They will mirror rootvg and are concerned about single points of failure. Which of the following features should be ordered？（）
A、Dual I/O planar， dual disk drives， dual SCSI adapters
B、Dual disk drive enclosures， dual disk drives， extra media bay
C、Dual disk drive enclosures， dual disk drives and dual SCSI adapters
D、Dual I/O planar， extra media bay， dual disk drives