GIS上的感应电压不应危及人身和设备的安全,在故障条件下,GIS外壳的感应电压不应大于下列何值?()
A.100V
B.60V
C.30V
D.24V
参考答案:A
下面的控件可作为其他控件容器的是( )。
A.DELETE DATABASE考生库
B.DELETE DATABASE考生库RECYCLE
C.DELETE DATABASE考生库DELETETABLES
D.DELETE DATABASE考生库DELETETABLES RECYCLE
Not until he left his home ______ to know how important the family was for him.
A.had he begun
B.did he begin
C.he began
D.he had begun