A.event通常指具有很大影响、意义大的事件或运动会的比赛项目.如：
Can you remember the events which happened in the 1960s?
The Autumn Uprising is a great event in China's histroy.
There are 300 different events in the Olympic Games.
B.affair 指已经发生或必须去做的事情,通常用复数形式指“事务”“事 态”如：the world affairs,foreign affairs.
C.business一词,作“事情”解释,一般指“公事”“正事”“商业事务”,强调任务,职务等指派的工作.如：
He is on business.
It's none of your business.
D.matter 意思为“毛病”、“问题”,通常指“要注意的事情”.如：
What's the matter with you
It's a different matter.