up to mischief

基本解释

Have you been up to mischief again?
你是不是又擣蛋了？
They look cute, but they are often up to mischief.
他們看起來很聰明，但是他們經常惡作劇。
33ff.net
Given an unusual amount of free time on their hands outside of working hours, with little in the way of entertainment options, some delegates got up to mischief.
由於在工作之外擁有了大把的業餘時間，再加上沒有什麽可以選擇的娛樂項目，於是某些美國代表就開始搞惡作劇。

And now in the 21st century, they are up to mischief.
FORBES: Mr. Market Will Get His Pound Of Flesh...And Then Some
Classic Halvorsen mischief was to come up with a cover design for one issue that parodied Business Week.
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Researchers at the Black Hat conference showed just what mischief a commonly used UK PoS terminal could get up to when they inserted a chip-and-pin card crafted with malicious code.
ENGADGET: Security experts hack payment terminals to steal credit card info, play games