值得的花費
還是同一個「先投、後收」，只是回報不一定是錢，而是「日後用得上、幫得上你」。把買東西這件事當成一筆划算的投資來看。
worthwhile purchase · noun · B2
Something you buy or do now because it will be useful or helpful to you later.
值得的花費
核心畫面
You can picture investment as putting something valuable into a thing now so that it grows and gives you more back later — you plant money into a business or a house, then wait for it to return bigger. Hold that one picture and the rest follow: the money or thing you bought is itself an 'investment', and so is the time, energy, or feeling you pour in hoping for a payoff down the road.
可以把 investment 想成：現在把一樣有價值的東西「投進去」，等它長大、日後給你更多回來——你把錢種進一間公…更多收起
可以把 investment 想成：現在把一樣有價值的東西「投進去」，等它長大、日後給你更多回來——你把錢種進一間公司或一棟房子，再等它變多回到手上。抓住這個「先投進去、之後拿更多回來」的畫面，其餘用法就順下來了：你買下的那筆錢或那樣東西本身就是一筆 investment；而你為了日後回報而投入的時間、精力、感情，也是同一種「先投、後收」。From the picture
投入心力
把「投進去的東西」從錢換成時間、精力、感情：你大量投入某件事，期待它有所回報，於是同一個畫面就用在心力上。
investment of time/energy · noun · B2
The large amount of time, energy, or feeling that you put into something.
投入
Also in this word
investment (money) · noun · B2
The act of putting money into something to earn more money later, or the money itself.
投資
原始詞典資料5 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
investmentnoun/ɪnˈvɛstmənt/
- 1
The act of investing, or state of being invested.
- Giving your children a good education is a wise long-term investment.
- 2
businessfinanceA placement of capital in expectation of deriving income or profit from its use or appreciation.
- An investment in ink, paper, and steel pens.
- Hidden behind thickets of acronyms and gorse bushes of detail, a new great game is under way across the globe.[…]The current power play consists of an extraordinary range of countries simultaneously sitting down to negotiate big free trade and investment agreements.
- 3
obsoleteA vestment.
- Whose white investments figure innocence.
- 4
governmentmilitarypoliticsThe act of surrounding, blocking up, or besieging by an armed force, or the state of being so surrounded.
- the investment of the fort
- In 1858, the Governor of Kuangsi applied for his services, but the Viceroy Tsêng Kuo-fan, under whom he had served for a number of years and who recognised his value, declined to part with him. In 1860 he assisted in the defeat of the rebel reinforcements at the Hsiao-ch‘ih post station and took part in the capture of Taihu, investment of An-ch‘ing and destruction of the rebel camp at Linghu. For his services in the capture of Anch‘ing he was rewarded with the title of Baturu and placed on the list of Brigade Generals. He was next sent to Chihchow in Anhui to make reconnaissances of the country and occupy the commanding situations.
- 5
A mixture of silica sand and plaster which, by surrounding a wax pattern, creates a negative mold of the form used for casting, among other metals, bronze.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。