The two boys _____ late yesterday. [ ]
A. are all
B. are both
C. were all
D. were both
答案:D
在进行危害评价时要考虑的三种状态没有()
A.正常
B.异常
C.现在
D.紧急
ZXA10 F820可以提供以下接口()。
A.上联口
B.以太网接口
C.E1/T1接口
D.VOIP语音接口