on the alert

基本解释

Often on the alert, she checks once but twice in the event...
她縂是警惕著，一個事情上檢查了一遍又一遍。
He whose expectation does not lead him to be on the alert for its coming will get but little.
所以一個人的期待，倘使不能警覺到神助之將臨，所得必屬稀少。
We are therefore campaigning for authors, researchers and editors to be on the alert for plagiarism and to work against cultural misunderstandings.
因此我們正在幫助論文作者、研究人員以及襍志編輯小心提防剽竊，而且還要對抗文化上的誤解。

For the first time the W.H.O.raised its alert level from phase four to phase five on April twenty-ninth.
because all we konw now it's orange alert, the alert level has gone up or gone down We don't really know what it goes on behind the scene.
我們都知道現在是橙色警報，警戒線時高時低,我們真的不知道,事情背後是如何処理的。
普林斯頓公開課 - 國際座談會課程節選
But it has taken on new urgency,coming one day after the World Health Organization raised its global swine flu alert to Phase 4 on the six-point scale.

He said he had warned all his employees to be constantly on the alert.
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