on guard against

基本解释

Thus, you should be on guard against this confused mapping.
因此，您应该谨防这种有混淆的映射。
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.”
“李导游曾经提醒过我们要提防小偷，不过Handy却不以为然：”意大利没有人们说的那么乱，不过传闻什么的听起来也吓人的很。
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.
君主应该防范他们，对他们感到害怕，把他们当作公开的敌人来对待，因为在困难时期他们总会促成他的垮台。

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.
艾肯鲍姆在书中提到,他特别提醒我们,不应该赞同拟声现象，拟声就是认为声音能反应它所表达的意思。
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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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