题目内容：

DO you have an Art Festival each year ___May?A.in B.on.
oh ,my god!I lost a set of keys .do you see___?
Sorry ,but you can go to the Lost and Found case.
A.them B.they C.their

优质解答

A 在月份、年份中都用in
A see后面接宾格作宾语,用them（ B是主格,作主语,C是形容词,他们的）