I don't know _________ he will come tomorrow._________ he comes,I'll tell you.选什么,为什么?

问题描述:

I don't know _________ he will come tomorrow._________ he comes,I'll tell you.
选什么,为什么?

就选D!前半句是宾语从句,if当是否讲;后半句是真实条件句,if当如果讲.其实,做这道题时,最好确定的是后半句,真实条件句的结构:if从句用一般现在时,主句用将来时.这样,很容易锁定答案的.