以下参数之间一一对应的为（）。
A.NSE---BSC
B.PVC---BTS
C.BVC---Cell
D.NSVC---MFS
参考答案：A, C
— Have you known Mr. Wang for a long time?
— Yes, since he _____ to our school. [ ]
A. has come
B. comes
C. had come
D. came
工作票延期手续能办理（）次，如果再延期，应重新签发工作票。
A.1
B.2
C.3
D.4
