1、to lead a dog's life 形容人过着贫困潦倒、惨不忍睹的生活Tom's been leading a dog's life since he got divorced.

　　汤姆自离婚后一直过着混沌潦倒的日子。

　　2、dog eat dog 残酷、竞争激烈

　　Some people say we live in a dog-eat-dog world.

　　有人说，我们生活在一个竞争激烈的世界。

　　3、work like a dog 指一个人努力、卖命地工作They say that to be successful, a person has to work like a dog.

　　他们说，一个人想要成功就得拼命工作。

　　4、dog-tired 筋疲力尽

　　Such hard work can make him dog-tired.

　　如此坚辛的工作使他疲惫不堪。

　　5、sick as a dog 病得严重

　　The situation would be even worse if she became sick as a dog.

　　如果她病得厉害，情况会更糟。

　　6、Every dog has its days.每个人都有属于自己的运气/每个人都有时来运转的一天Don't give up and try your best I believe every dog has its day.

　　不要放弃，继续努力，我相信每个人都会有成功的时候。

　　7、You can never teach an old dog new tricks. 老古董学不会新东西You're never going to teach your father at the age of 79 to use a computer. You can't teach an old dog new tricks, you know.

　　不要指望教你79岁的老父亲学会电脑。年长的人学不会新事物。

　　8、meaner than a junkyard dog 冷漠，不友好He is a man meaner than a junkyard dog.

　　他是一个残酷、冷漠的男人。

　　9、His bark is worse than his bite. 刀子嘴、豆腐心I wouldn't be scared of her if I were you. Her bark's a lot worse than her bite.

　　如果我是你，我不会怕她。她是个刀子嘴，豆腐心的人。

　　10、let sleeping dogs lie 不要自找麻烦、自讨苦吃Green is trying to let sleeping dogs lie.

　　格林在努力避免招惹是非。

　　11、the dog days of summer 一年中最热的三伏天I can do nothing except for swimming in the dog days of summer.

　　在三伏天里，除了游泳，我什么事也做不成。

　　12、to rain cats and dogs 下倾盆大雨

　　In the middle of the picnic it started to rain cats and dogs, and everybody got soaked.

　　野餐进行到一半时，天开始下起大暴雨，弄得每个人都湿透了。。