catch on例句

Eddie slipped the safety catch on his automatic back into place.
埃迪将自动步枪的保险栓重新拉上。

Wait a minute! I'm beginning to catch on.
等一下！我开始有点懂了。

Being a foreigner, he did not catch on the joke.
他是个外国人, 未能理解这个笑话的含意.