waste energy on a lost cause or unalterable situation
作无用功,徒劳无益。
作无用功;徒劳无益
It is useless to flog a dead horse.
鞭死马无益;勿旧调重弹。
It is useless to flog a dead horse.
鞭打死马,徒劳无益。
Son, we 've been over this so many times. The answer is "no". Don't flog a dead horse!
儿子,这个问题我们已经讨论过很多次了。回答是“不能”。别老把时间浪费在没有希望的事情上。
waste energy on a lost cause or unalterable situation
作无用功,徒劳无益。