Question

I don't know if he ________ tomorrow．If he ________, I'll meet him．

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

Answer 1

A
第一個if意為“是否”，引導(dǎo)賓語從句，可用于一般將來時；第二個if意為“如果”，引導(dǎo)條件狀語從句，用一般現(xiàn)在時代替將來時。