关于down

关于down
He broke down. 他崩溃了；
Upside down. 上下颠倒了；
Calm down. 冷静点；
4.She walks up and down. 她来回踱步；
Put it down. 把这东西放下来；
You look down. 你看起来很沮丧；
Step down. 下来。 ???