occasion
有特别意义的、正式的时间点或场合
event
发生的事情或活动,可以是正式或非正式的
The state dinner was a formal occasion attended by dignitaries from around the world.
国宴是一个正式场合,来自世界各地的权贵人士出席。
The school organised a series of cultural events to celebrate its centenary.
学校组织了一系列文化活动来庆祝建校百年。