lost cause

1. N-COUNT If you refer to something or someone as a lost cause, you mean that people's attempts to change or influence them have no chance of succeeding. 必?cái)o疑的事; 無望成功的人

They do not want to expend energy in what, to them, is a lost cause. 他們不想把精力投到他們認(rèn)爲(wèi)注定不會(huì)成功的事中去。