They wanted to have ___for Lucy.

问题描述:

They wanted to have ___for Lucy.
A.a surprise party.B.a surprising party 答案给的是A .为什么不是B呢?

surprise party 是固定短语---惊喜聚会(一种聚会的形式)
因此,虽然b也是对的,但这里A 更具有优先权