Everyday English: Carry coals to Newcastle.

向煤区运煤。多此一举。

Selling refrigerators to the Eskimos is like carrying coals to Newcastle.

向爱斯基摩人推销电冰箱简直是白费力气。

To offer him money is to carry coals to Newcastle; he is already very wealthy.

给他钱是多此一举，他已经很富有了。

Mary sent chocolate to her aunt in Switzerland. I told her that it was like bringing coals to Newcastle.

玛丽给她住在瑞士的姨母寄送巧克力，我告诉她这是多此一举。

It would BE like carrying coals to Newcastle if another post office opened in the neighborhood; there are already three now.

如果在此附近再开一家邮局，简直是多此一举。现在已经有三家了。