1. 词汇：dead horse

释义：Something—especially an issue or topic—that is no longer of any use or relevance. （徒劳的事，没有丝毫希望成功的事情）

例句： Forget it! Don’t waste time whipping a dead horse.

算了吧，别浪费时间做徒劳无益的事情。

You're flogging a dead horse by asking Jim to lend you money-he hasn't even enough money for himself.

你要吉姆借钱给你，这是徒劳，他的钱甚到不够他自己花。

You'll be flogging a dead horse if you keep trying to get Walter to make a contribution, you know how mean he is.

如果你坚持想要沃尔特作贡献的话，你会白费劲的，你知道他是极其吝啬的。

He's flogging a dead horse by trying to persuade people to use canals instead of roads.

他拼命地劝人不要使用公路而去使用运河，真是枉费口舌。

Jack was then working for a dead horse for he had been paid in advance.

杰克已预领工钱，所以那时他虽然干活，却再也得不到报酬了。

2. 词汇：hobby horse

释义：A topic to which one constantly reverts. （反复唠叨的话题，别人已经听腻了而自己却乐此不疲的话题）

例句：Is Sam boring you again with his hobby horse about holding a party some day?

萨姆又在谈论某天举办晚会的老话题了，那使你觉得厌烦吗？

No, I don't want to talk to Sam.I can't stand another minute of him riding his hobby horse about invader from space.

不，我不想同萨姆讲话。我再也不能忍受听他讲来自太空的移居者了，哪怕是一分钟。

3. 词汇：harp on one string

释义：To dwell tediously and repeatedly upon a single subject or topic, especially in complaint. （反复说同一件事情，老调重弹）

例句：Mark is always harping on one string about how little money he makes. I wish he would come up with something new to talk about!

马克总是唠唠叨叨地说他挣的钱少得可怜。我希望他能想出一些新的话题来谈!

I get it, you don't like your job. Quit harping on one string!

我理解你的意思了，你不喜欢你的工作，别再重复说了。