—When is Henry’s birthday party Lynn?—The 18th about there o’clock in the afternoon.A.

问题补充：

—When is Henry’s birthday party, Lynn?

—The 18th , about there o’clock in the afternoon.

A. in

B. at

C. on

D. to

答案：

A. in

(答案→)B. at

C. on

D. to

解析：考查介词,在表达时间时,on表示在具体的一天,in表示在一个时间范围内,at表示在几点钟,to表示差几分到几点钟,。根据下文about there o’clock in the afternoon.

大约下午三点钟，可知表示的是具体时刻，故选B。