2。表示“在上、下午”，“在晚上、傍晚”用in，如要表示“某日上午”早些時候或晚些時候也用in，表示什麽月、什麽季度、什麽年份、什麽世紀要用in
3。但是若在morning等詞前有修飾語時（如cold、fine等）用on
在某日的早晨也用on
題目：
1）She got married _ 22.
2) We left Hangzhou _ the afternoon of October 15.
3) He called me _ Sunday morning.
4) He phoned me _ the early morning of June 4.
5) They arrived _ the late afternoon of 20th December.
6) My daughter was born _ July 1961.
7) The First World War broke out _ 1941 and ended _ 1918.
8) I shall take a holiday _ summer.
key:1)at 2)on 3)on 4)in 5)in 6)in 7)in in 8)in
從我的語法書上抄的，累~~~