This refers to a final agreement that has been reached. For example, the buyer and seller of a home agreed upon the price: “It’s a done deal”. Changes cannot be made to the agreement unless everyone agrees first. Otherwise, it is ‘not a done deal’: “we agreed on a price, but now the buyer wants more things to be included, so, it’s not a done deal yet.”
交易完成
這句話是說大家已經達成最後的共識。比如買賣雙方已經談妥價錢，就可以說”It’s a done deal.(交易完成)” 除非每個人都同意，否則就不能對協議的事做任何更改，不然就無法完成交易了，例如：「我們本來都談好價碼了，但現在買家卻想要多坳一點東西，所以我們還無法完成交易。」