Question

The students play games ________ Thursday afternoon.

1. A.
   on
2. B.
   at
3. C.
   in
4. D.
   of

Answer 1

A
表示在某一天的上午、下午、晚上，介词用on，而笼统地说在上午、下午、晚上用in。试比较：in the morning, on Sunday morning。