I don’t know if he ____ us; if he ____, I’ll let you know.

  I don’t know if he ____ us; if he ____, I’ll let you know.

1. A.
   will come and help; comes
2. B.
   comes and helps; will come
3. C.
   will come and help; will come
4. D.
   comes and helps; comes

     I don’t know if he ____ us; if he ____, I’ll let you know.

A. will come and help; comes     B. comes and helps; will come

C. will come and help; will come   D. comes and helps; comes

  I don’t know if he ____ us; if he ____, I’ll let you know.

从所给的四个选项中选择最佳答案

I don't know if he ______, if he ______, I'll let you know．　　　

[　　]

A．will come, comes　　　B．comes, will come

C．comes, comes　　　　D．will come, will come