He is a crack shot.

他是个神枪手

The policeman are cracking down on underage drinking.

警察开始对那些未到法定年龄饮酒的人做出了严厉的惩罚。

That movie really cracked me up .

这部电影真的是太好笑了

You'll crack up if you carry on working like this.

你再这样干下去，身体会垮掉的。

Are you on crack？

你疯了吗？

She cracked a joke

她讲了个笑话

He finally cracked a smile

他终于是笑了。