all in a day's work

Definition: nothing special, part of the routine
這句話的意思是“沒什么特別的，司空見慣”

例句：

Don't worry about it. It's all in a day's work.
別擔心，這沒什么特別的，

Cooking is all in a day's work.
燒飯是常有的事兒。

All work and no play makes Jack a dull boy.

Definition: Idiom meaning that you need to have fun in order to be a happy, healthy person
這句話就是傳說中的“只工作不玩耍，聰明的孩子也變傻”。

例句：

Go home! Remember: All work and no play makes Jack a dull boy.
快回家吧，要記住：只工作不玩耍，聰明的孩子也變傻。

I'm worried about him. He hasn't yet understood that all work and no play makes jack a dull boy.
我很擔心他，他還沒有明白過來，只工作不玩耍，聰明的孩子也變傻。

dirty work

Definition: Necessary, but uninteresting, or difficult work
這句話的意思是“必須要做的但很無聊或很難的工作”，其實也就是做苦工，或者是吃力不討好的工作。

例句：

He did the dirty work on that project.
他在那個項目中做的是吃力不討好的活兒。

Have you got around to doing the dirty work yet?
你已經在找時間做這個很無聊的工作了嗎？