继电器和插座的绝缘电阻应不小于（）MΩ。
A.100
B.200
C.300
D.400
参考答案：A
There are_________ students in my school._________ students in my school is over 5000.
A．a number of, A number of
B．the number of, The number of
C．the number of, A number of
D．a number of, The number of,
下颌骨的薄弱部分不包括
A．乙状切迹B．髁突颈部C．颏孔区D．下颌角E．正中联合
