1. Chip in 凑钱

We all chipped in to buy Jennifer a going-away present.
大家凑钱买一个送别礼给詹妮弗。

释义：

源于赌博业。

chip: 筹码

chip in: 人们往赌桌上扔筹码

2. Clean up one's act 洗心革面，重新做人

You'd better clean up your act if you want to go to a good school.
如果你想进好学校洗心革面，奋发图强。