I don’t know when he . But if he I’ll ring you up.A. comes will comeB. will come will

问题补充：

I don’t know when he . But if he , I’ll ring you up.

A. comes, will come

B. will come, will come

C. comes, comes

D. will come, comes

答案：

A. comes, will come

B. will come, will come

C. comes, comes

(答案→)D. will come, comes

解析：本题考查动词时态。第一个空前的when引导宾语从句，此处用一般将来时；第二个空前的if作“如果”讲，引导条件状语从句，主句用了一般将来时，故此处用一般现在时表示将来。