一、necessary (for) 二、required
參考例句：
Help oneself
自取所需(食等)
We are no longer free to choose the things we want.
我們已經無法獨立自主地選購自己所需的東西了。
Those that are more saturated require less oxygen absorption to become rancid
飽和度較高的酸敗時所需吸收的氧氣較少
Please enter your password to retrieve preferences from the directory server XX.
請輸入從目錄服務器XX檢索首選項資訊所需的口令。
These investments have largely been funded with debt.
這些投資專案主要靠借債來籌措所需資金。
The organization shall plan and develop the processes needed for product realization.
組織應策劃和開發產品實現所需的過程
。Our camp is well stocked with everything we need for a short stay.
我們營中凡短期居留所需之物都有充分的儲備。
Include hand washing and drying facilities and properly supplied with soap and other needed supplies
有洗手和烘乾設施,需提供肥皂和其他所需的物質
The time required after energizing a device, before its rated output characteristics begin to apply
從裝置通電到它開始提供額定輸出特性之間所需的時間。
More than enough is too much
超過所需就是太多
necessary是什麼意思：
adj. 必要的；必需的；必然的；不可避免的
n. 必需品
It is necessary to delimit the anomaly clearly.
清楚地圈定異常是必要的。
The redress of mistakes is necessary.
糾錯是必要的。
It's necessary to operate on him.
必須給他做手術。
Cases it deems necessary to try.
認為應當由本院審理的.案件。
It is necessary to delimitate the anomaly clearly.
清楚地圈定異常是必要的。
required是什麼意思：
adj. 必須的，必修的
Is the requirement compulsory?
必須按這個需求做嗎？
In practice, this will often require a prioritization of your job requirements.
實務上，這往往需要重新調整工作的優先順序。
All systems requiring accurate timing will require a crystal.
所有需要精確定時的系統都要用晶體。
Excision of an obnoxious passage was required.
有一段引起反感的文字必須刪掉。
require or ask for as a price or condition.
要求或者請求價格或者社會地位。
