on guard

基本解释

The world is alert and on guard as never before.
世界从没有向现在这样保持警惕和戒备。
All this time, the mother is constantly on guard.
在这段时间内，章鱼母亲一直在警戒状态。
If we are alert enough, we’ll notice that we are always on guard.
如果我们足够警惕，你会发现我们经常是在站岗。

A pig and a guard llama also live on the farm.
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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The Essex stood half over the other prophet as if it were pleased to guard what it had finally brought down. The man didn't look so much like Haze lying on the ground on his face without his hat or suit on. A lot of blood was coming out of him and forming a puddle around his head.
埃塞克斯看着这个先知，好像很高兴地守卫着,自己撞倒的这个人，这个男人看起来与海斯并不相像,没有戴着帽子或穿着西装趴在地上，一大堆血,从他的体内涌出，在头部附近形成了一个水坑状的东西。
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Such regimes are therefore inherently belligerent and democratic nations must always be on guard against them.
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防范
The supervision on financial exposure is the further step to quantify the exposure and it is the basis to take measures on keeping on guard and dissolving it.
对金融风险的监测，是识别金融风险的进一步量化，是采取措施防范和化解金融风险的依据。
军事学
站岗，放哨，值班