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。

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Suddenly, he heard something scaring: "Paula! Paula!" a man shouted crazily. Grant turned around quickly.

突然，他听到一个骇人的声音，一个男人疯狂地叫喊道：“宝拉！宝拉！”。格兰特迅速转过身去。

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Investors concerns over all this aren’t likely to go away any time soon, unless the ITC judges suddenly start working as quickly as smart-phone engineers.

投资者的忧虑在短期内将难以消散，除非国际贸易委员会的办事效率突然变得跟智能手机工程师一样快。

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The Lady in Black raised her head suddenly and quickly looked into the woman's face.

VOA: special.2010.05.15

Publishers might be able to determine when interest in a fiction series is flagging if readers who bought and finished the first two books quickly suddenly slow down or quit reading later books in the series.

WSJ: Your E-Book Is Reading You

Several of the lawmakers have been at the forefront on the issue of sexual assault in the uniformed services and have introduced legislation in Congress that suddenly is moving quickly.

NPR: Lawmakers, White House Discuss Sexual Assault

Market watchers said there was not a specific reason for gold prices to suddenly drop so quickly on Wednesday, but that there were several signs, including a 93% bullish market sentiment reading by Market Vane on Monday.

FORBES: FOCUS: Gold's Break Deemed 'Healthy' For Market Direction