be on the alert

• 注意

be on the alert的用法和样例：

例句

1. Fasten on what the teacher is saying.
   注意听老师说。
2. She always wants to be the focus of attention.
   她老想成为人们注意的中心。
3. Be on the watch for thieves in this crowd.
   提防人群中有小偷。
4. Be sure to be watchful or alert.
   必须留神，千万要提防。
5. Keep a vigilant eye on the imperialist jackals.
   对帝国主义的走狗要保持警戒。
6. My reins also instruct me in the night seasons.
   我的心肠在夜间也警戒着我。