on guard

常见例句

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。
耶鲁公开课 - 文学理论导论课程节选
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。
耶鲁公开课 - 1945年后的美国小说课程节选

Such regimes are therefore inherently belligerent and democratic nations must always be on guard against them.
CENTERFORSECURITYPOLICY: What Undid the Middle East 'Peace Process'
While he was on guard duty in a watchtower that morning, insurgents attacked with rocket-propelled grenades.
WHITEHOUSE: The White House
Other officers on guard looked like they were trying hard not to pass out from the heat.
FORBES: Remembering the Road to Baghdad