What will you do if it tomorrow? A. will rainB. is rainingC. rainsD. isnt rain

问题补充：

What will you do if it tomorrow?

A. will rain

B. is raining

C. rains

D. isn rain

答案：

A. will rain

B. is raining

(答案→)C. rains

D. isn rain

解析：if引导的条件状语从句用一般现在时。