He is very quick to catch on to things.

他领悟能力很强。

Eddie slipped the safety catch on his automatic back into place.

艾迪把自动步枪的保险拉到了位。

At first I didn't catch on, then I suddenly saw the light.

始而不解，继而恍然。

Some scares catch on: others do not.

有些恐慌传播开了，有些则没有。

Could such civil resistance catch on?

难道是这种非军事性的抵抗流行吗？