be on the alert

基本解释

We must be on the alert to discharge our responsibilities toward the friendly countries.
我們必須警惕自己放棄對友好國家的責任的做法。
Our company has informed us that there have been many cases of piracy, and warned us to be on the alert .
公司已經通知我們，最近連續發生多起海盜襲擊船舶事件，因此要求我港提高警惕。
Currently, first, the BRICs should be on the alert that hostile powers in developed countries may make mischief between them under the cover of ideology and history-made problems;
儅前，它們一是要特別警惕發達國家中的敵對勢力利用意識形態和歷史遺畱的問題挑撥離間；

General Fonseka,in the letter, says Sri Lanka asked India on October 15 to place troops on alert in case they would be needed to intervene to foil a coup on the island.

Planned Parenthood has to be on the alert already given the episodes over the last month.
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You can be the one to be on the alert for their financial safety.
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When a fifth wave is extended, we should be on the alert for a sharp correction once that wave completes its run.
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