Drivers must be on the alert for traffic signals.

The whole navy was placed on full alert.

整个海军都处于全面戒备状态.

The district was put on red alert during a terrorist's bomb scare.

这个地区在得到恐怖分子炸弹恐吓后作了应急准备.

A sparrow is very alert in its movements.

麻雀行动非常机灵.

Alert readers may have noticed the misprint in last week's column.

细心的读者可能已经注意到上周专栏中的印刷错误了.

He is a man alert in problem.

他是个留意问题的人.

If our environment cools, then messages from the skin alert the body's thermostat.

如果外在环境变冷，体表会将这一信息传递给身体的体温调节中枢。

He had been spotted by an alert neighbour.

一个警觉的邻居发现了他。

The all clear was sounded about 10 minutes after the alert was given.

警报发出10分钟后又响起解除的信号。

Sirens sounded an end to the red alert.

警报声宣告了红色预警的结束。

Soldiers and police have been put on alert.

士兵和警方都已进入警戒状态。

Due to a security alert, this train will not be stopping at Oxford Circus.

由于安全戒备的原因，该次列车在“牛津街口广场”站将不停留。

I managed to walk around unchallenged for 10 minutes before an alert nurse spotted me.

我四处走动了10分钟，没有受到查问，之后一位警觉的护士发现了我。

"Will you call the board to alert them that I feel I should resign?" — "I'll do it. But I think you're copping out."

“你能不能给董事会打电话，提醒他们我觉得自己应该辞职？”——“我会的，但我认为你这是在逃避责任。”

All the Plymouth hospitals are on red alert.

普利茅斯所有的医院都处于紧急状态之中。

Her expression was watchful and alert.

她露出一副察言观色、处处提防的表情。

Four seconds later, the controller issued a low-altitude alert to the pilot.

四秒钟后, 管制员向该飞行员发出了 低高度 警告.

Always alert to potential attacks and thwart them before they happen.

时刻警惕可能存在的抨击,先发制人.

The " vigilantes " in the market are supposedly alert to any inflationary threat.

按理,市场中的 “ 积极分子 ” 会提防任何通胀威胁.

A good teacher should be very alert to his students'progress.

一位好的教师应对学生取得的进步非常敏感.

And they had to be alert to Chelsea's countering.

同时他们亦需要提防切尔西的反击.