look out
To be watchful or careful; take care:
小心,当心；注意：
If you don't look out,you may fall on the ice.We looked out for each other on the trip.
如果不小心的话,你会在冰上摔倒的.我们在旅途中互相照看
=watch out
watch out[vi]注意……,留神……；监视……,警戒……（for 名）
Watch out!The man has a knife.
小心!那个男人带着刀子!
watch out for cars
注意汽车