(1)投资(investing of money)[U，N(in)]：capital～资本投资;～in real estate/enterprise/oil stocks 房地产/企业/石油股票投资;a promising field for～有前途的投资领域;By careful/wise～，he obtained a big profit. 他靠精心/明智的投资而获巨额利润。

(2)投资额(amount of money used for the act of investing)[C，N(in)]：make an～of $100，000 in a project 在一工程上投资10万美元;a good/poor/lucrative/risky/safe and sure/sound～值得/不当/有利/冒险/安全可靠/稳妥的投资;heavy/huge/long-term/overseas～s 巨额/巨额/长期/海外投资;～bank/company 投资银行/公司;

(3)(可)投入资金或时间的事物(sth on which money or time has been spent in the hope of future advantage or profit)[C]：Real estate/A new tractor is a good～. 房地产/一台新拖拉机是一项很好的投资。It might be a better～of time to teach children to cook. 教孩子做饭可能是一种较好的时间投入。