on alert

Soldiers and police have been put on alert.

士兵和警方都已进入警戒状态。

On alert the ear should never droop, bend, or crease.

警惕时,耳朵决不下垂 、 弯曲 、 或折叠.

Emergency services were put on alert.

应急服务时刻准备着.

I think, again, it puts people on alert all the time.

我想必定是周而复始的, 它使人们一直处于高度紧张中.

HK on alert after typhoon sweeps through Philippines.

香港做好“迎接”台风准备.

Please be on alert against strangers in your premises.

提高警惕,尤其注意租区内的陌生人.

Although they may appear dead, they sometimes spring up to attack, so always be on alert.

它们也许看上去已经死去, 但有时它们也会奋起战斗, 时刻处于警戒状态.

Some 7,000 police will be on alert.

7000警察将在戒备.

This will leave the earth vulnerable, so we're still on alert.

这会让地球容易被攻击, 所以我们仍然处于警戒状态.

Bombers were put on alert during the crisis.

危机时刻,轰炸机处于警戒状态.