on
1.日期前面的on有时省去。例如：
- The People's Republic of China was established (on) 1 October, 1949.
- The Second World War was finished (on) 3 September, 1945.
- John Galsworthy was born (on) 4 August, 1867 and died (on) 31 January, 1933.
- (On) May Day we are to take part in the gala performance.
- I met him again (on) the following day.
2.关于in the morning和on the next morning等，参见in 4
3.下面两句里的on是美国用法，在英国通常用in：
- He lives on the next street.
- She often reads on a railway train.
在英国说on a railway journey，但in a railway train。
4.注意下面两句里的on the river意思不同：
- He lives in a house on the river.（在河的旁边）
- He sails on the river every Sunday.（在河上）
