work one's butt off 很努力地(做一件事)

A: I can't believe all my work is gone just like this. I've worked my butt off on this all day!
A: 我不敢相信我的心血就这样丢掉了!我今天整天辛辛苦苦都在搞这个!

B: What happened? Computer crashed?
B: 怎么啦? 计算机当了吗?

美语里不少口语都跟"butt"(屁屁)有关, 像 "kick ass"、"kiss ass"这里的"work one's butt off" 也是。还有一个"freeze one's butt off"(冷得把屁屁冻僵)也是喔!