客户停机保号期间仍收取客户的()。
A.号码占用费;
B.号码通信资源费;
C.移动通信资源占用费;
D.信道占用费。
参考答案:A
设计圆柱齿轮传动时,小齿轮的齿面硬度与大齿轮的齿面硬度的关系是( )
A.大于 B.等于C.小于 D.大于等于
Computers are so popular in our country that every pupil knows _____ e-mails. [ ]
A. how can he send
B. how does he send
C. how to send
D. how sending