A flash mob is a group of people who come together suddenly in a public place, do something unusual for a short period of time, and then quickly break up.

快闪族，是指一群人突然在公共场所聚集，在短时间内做一些不寻常的事情，然后迅速散开。

Flash mob: a group of people gathered through online social networking.

快闪族：指一群人通过网络社交活动聚集在一起。

Flash mob: a group of people gathered through online social networking.

闪族：指一群人通过网络社交活动聚集在一起。

Youth activists, meanwhile, organised a flash mob in a House office building today.

与此同时，年轻的积极分子们今天在众议院的一幢办公楼内组织了一次快闪行动。

This was the first case of the globally renowned "Flash Mob" landing in Changchun, China.

这是风靡全球的“快闪行动”首次登陆中国长春。