1. act up 胡闹，出毛病

The children started to act up as soon as the teacher left the room.

老师一离开教室，孩子们就闹起来了。

2. ad lib 即兴而作，随口编

The comedian ad libbed most of his routine.

那个喜剧演员大多是即兴表演。

3. blah-blah-blah 说个不停

All she does is go "blah-blah-blah" all night.

她整夜说个不停。

4. hit it off 投缘，一见如故

They hit it off instantly and have been good friends ever since.

他们一见面就很投缘，从此成了好朋友。

5. zit 青春痘

Why is it that every time I have a hot date, I break out with a big zit

on my face?

为什么每次我有重要约会时，脸上都会冒出一个很大的青春痘呢？