—Look! There so many people in the park.— Nobody likes to stay at home Sunday morning. A.

问题补充：

—Look! There so many people in the park.

— Nobody likes to stay at home Sunday morning.

A. in

B. on

C. at

D. to

答案：

A. in

(答案→)B. on

C. at

D. to

解析：介词。具体到某一天的上午、下午或晚上，要用介词on.