You should be on guard when a stranger comes to your doors.(當陌生人站在你家門前是，你應該有所堤防。)

After all, cities are hyper-social places, in which residents must be constantly on guard, and have mathematically more opportunity to experience stressful interaction.(畢竟，城市是一個具有超社會性質的地方，身處其中的居民們必須時常保持警惕，并且擁有在數量上占優的機會去體驗充滿壓力的相互作用。)

If we are alert enough, we'll notice that we are always on guard.(如果我們足夠警惕，你會發現我們經常是在站崗。)

The animal that goes to a favorite food-foraging location and sees signs that a predator was there - but not the predator itself - may be on guard the next time.(在某些情況下，我們會幻想自己的先人又復活了。“一個動物到它最喜歡覓食地點，看到有個食肉動物一在那里的跡象，但不是食肉動物本身，可能是上次（下次）在那里站崗。)

The world is alert and on guard as never before.(世界從沒有向現在這樣保持警惕和戒備。)

Security was tight around the launch site, where about 1, 600 police were on guard.(安全措施緊密圍繞發射場，其中約1600名警察守衛。)

On guard: Mexico City is at a virtual standstill.(站崗：墨西哥處在一個實際意義上的停滯狀態中。)

Then they turn gracefully and walk past the two police officers on guard-the officers try not to stare-into the hotel ballroom.(然后，她們優雅的轉過身去，走向那些不敢盯著她們的兩名警官，然后進入賓館的舞廳。)

The soldier who is on guard is my friend.(那個站崗的戰士是我的朋友。)

Distrust increases tension and negative "on guard" behavior, which can erode the spirit of the team and ultimately productivity.(不信任會增加緊張和消極的“防范”行為，這會破壞團隊精神而最終影響生產力。)