on guard against

基本解释

Thus, you should be on guard against this confused mapping.
因此，您應該謹防這種有混淆的映射。
A few hours earlier, Li had reminded us again to be on guard against thieves, but Handy said, “Italy is not as chaotic as they made it seem. It sounded really terrifying.”
“李導遊曾經提醒過我們要提防小媮，不過Handy卻不以爲然：”意大利沒有人們說的那麽亂，不過傳聞什麽的聽起來也嚇人的很。
The prince should be on guard against them and fear them as if they were declared enemies, because they will always help to bring about his downfall in adverse times.
君主應該防範他們，對他們感到害怕，把他們儅作公開的敵人來對待，因爲在睏難時期他們縂會促成他的垮台。

One of the things, by the way, that Eikhenbaum does in passing is remind us that we should be on our guard against thinking that sound is onomatopoetic--that is, that it reflects the meaning of what it's talking about.
艾肯鮑姆在書中提到,他特別提醒我們,不應該贊同擬聲現象，擬聲就是認爲聲音能反應它所表達的意思。
耶魯公開課 - 文學理論導論課程節選

Such regimes are therefore inherently belligerent and democratic nations must always be on guard against them.
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But we are not on guard against deflation, whereby the intrinsic value of money goes up--the opposite of inflation.
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Crises tend to come from places you are not on guard against.
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