We usually have a class meeting Monday afternoon.A. at B. inC. onD. to

问题补充：

We usually have a class meeting Monday afternoon.

A. at

B. in

C. on

D. to

答案：

A. at

B. in

(答案→)C. on

D. to

解析：在英语中，表示“在早上/下午/晚上”用in the morning；如果说是在怎样的早上/下午/晚上，就应该用介词on。所以本题选C。