a bad apple

基本解释

If a bad apple slips through screening(3) in the hiring process, he or she should be placed to work alone as much as possible, the study's lead author, William Felps, said.
本研究主要作者William Felps说如果一颗坏苹果溜进公司招聘榜，他或者她应该尽量被安排独立工作。
Ask a client's CEO, though, and he will likely tell you this: every CEO goes to bed at night worrying about a bad apple in their ranks—be it a rogue trader or a rogue consultant.
但随便问一位客户的CEO，他很可能会告诉你：每位CEO晚上睡觉的时候都在担心公司内部出现害群之马——不管它指的是一位流氓交易员，还是一位流氓咨询师。
John is really a bad apple. He always robs little girls´ bag.
约翰真是一个坏蛋。他总是抢小女孩的包。

BigSmart says Lamont is just a bad apple--the same line it used with Fournier in Maine.
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Apple without Steve Jobs in the past has been just a bad apple core.
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The first prominent abuse case, involving the officer who deployed pepper spray on a group of clearly nonthreatening women, is being investigated, yet tossed away as a bad apple.
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