on the alert
注意, 提防, 警戒, 警惕着, 处于戒备状态
例句与用法:
A feather floats about on the air, especially on a windy day. If there is a shower of rain, the feather will get wet and heavy with water, and then it will sink straight to the ground.
羽毛会在空中四处飘动,尤其是在多风的天气。如果遇上阵雨,就会因为淋上雨水变湿就沉,然后就会垂直落回到地上。
The bombers swooped on the air base.
轰炸机突袭空军基地。
This channel comes on the air every morning at 7 am.
这个频道每天早晨7点钟开始播放。
The news will be on the air tonight.
这个新闻今晚将要广播。
详细释义:
警戒着; 随时准备着
They have put the army on the alert.
他们已使军队进入戒备状态。