We have breakfast eight Sunday morning.A. at inB. at onC. to inD. in on

问题补充：

We have breakfast eight Sunday morning.

A. at, in

B. at, on

C. to, in

D. in, on

答案：

A. at, in

(答案→)B. at, on

C. to, in

D. in, on

解析：在表示时间时,in表示在一个时间范围;at表示在具体时刻;on表示在具体某一天.to表示差几分到几点。本句中八点为具体时刻,故用介词at.星期日上午为具体某一天,故用介词on,选B.