调度员可以用（）命令初步判断工业网主链路中断
A、ping
B、tracert
C、ipconfig
D、ipconfig/all
参考答案：B
— How are you today?
— I'm feeling even _____, I don't think the medicine is doing any good on me. [ ]
A. better
B. happier
C. worse
D. unhappier
各级GPS点均应埋设标石或标志，埋设标石时须使各层标志中心严格在同一铅垂线上，其偏差不应大于______mm。
A．2.0 B．2.5 C．3.0 D．3.5
