Question

【题目】Mike has no time to buy a gift for Alice. So he doesn’t know _______ her birthday party.
A.whether to take part in
B.if to take part in
C.whether to join
D.if to join

Answer 1

【答案】A
【解析】根据句意“迈克不知道是否该去参加聚会”可知，参加活动应选用take part in, 故应排除C、D；而if和whether 虽都表示“是否”，但和动词不定式连用必须用whether, 故选A。