机械泡沫和水型灭火器应按照生产厂家说明书要求的灭火剂进行再充装，灭火剂的出厂日期不应超过()个月。

A、1

B、2

C、3

D、4

I'm waiting for my friend.           , I'll go shopping alone. [ ]

A. If she comes

B. If she will come

C. If she doesn't come

D. If she didn't