coals to Newcastle
徒劳无功的行为
口语·表示多此一举或徒劳无功
英文释义
to do or bring something that is unnecessary or redundant
例句
Bringing ice to Antarctica is like coals to Newcastle—completely unnecessary.
典故来源
源自英国纽卡斯尔是著名的煤炭产地，向该地运煤纯属多余，比喻做徒劳或多余的事。