學個用語："Smell a rat"

In English, when we say we 'smell a rat' we mean we're suspicious of someone: we feel there's something wrong. Some examples：

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A: I read an article about a diet which makes you lose six kilos in one week. It says there is no need for exercise

B: Six kilos in one week?! That's impossible! I smell a rat!

Jane smelt a rat when she read a job advert for actresses in the newspaper. It said "no training or experience required", but they wanted someone "good-looking and open-minded".

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聞到老鼠？哈！這是指事有蹊蹺，有不妙之處，雖然你不是很清楚，但是覺得很可疑的事件或情況！尤其是遇到類似詐騙狀況時，這個就是很好用的詞！I (can) smell a rat. 老鼠rat，通常背後涵義是"鼠輩"、"卑鄙小人"，它除了當名詞外，也可以直接作動詞用，意思是背叛，"He rats me out." 就是他把我賣了。

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