Question

【题目】I don't know _______ he will come tomorrow. ________ he comes, I'll tell you.
A.if; Whether
B.whether; Whether
C.if; That
D.if; If

Answer 1

【答案】D
【解析】句意：我不知道他明天是否会来。如果他来，我会告诉你。If如果，引导条件状语从句；是否，引导宾语从句；Whether是否，引导宾语从句。That那，可以引导宾语从句。所以选D。