问题
选择题
—Mike invited us to take part in the party this Sunday.
— Is tomorrow his birthday?
A．Why not?
B．That’s all right.
C．What for?
D．What a good idea!
答案
答案：C
题目分析：根据Is tomorrow his birthday?可知，对方应该是很惊讶，不知为什么会邀请我们去参加晚会，故应该用what for。所以本题选C。
点评：完成本题需要弄清句子的意思，根据情景进行选择，另外what for“为什么”相当于why。