注釋：constraint n. [數] 約束；局促，態度不自然；強制
詞根：constrain
adj.
constrained 拘泥的；被強迫的；不舒服的
adv.
constrainedly 勉強地；強迫地；不自然地
v.
constrained 驅使；強迫；勉強（constrain的過去分詞）
vt.
constrain 驅使；強迫；束縛
例句：
(1) The boy felt constraint in her presence.
那男孩在她面前感到局促不安。
(2) The subject of this constraint is customer.
這個約束的主體是客戶。
(3) This very simple program declares the two decision variables: the constraint and the objective function.
這個非常簡單的程序聲明了兩個決策變量：約束和目標函數。
(4) You can name the constraint, but you do not have to.
您可以命名約束, 但這不是必須的。
(5) There have been several attempts to deal with this kind of constraint.
已經有人做了一些處理這類約束的嘗試。
(6) Well, here we have to use the constraint.
這里，我們必須使用約束條件。
(7) If the language is not supported, the constraint is ignored by the tool.
如果指定的語言不被支持, 約束將會被工具所忽略。
(8) An example of a constraint is "a customer must have exactly one legal address".
約束的一個例子是 “一個客戶有且只有一個合法地址”。

occasion n. 時機，機會；場合；理由
vt. 引起，惹起
詞組：
occasion segmentation時機細分；場合細分
Right Occasion合適的情境；適當時刻
occasion n場合；重大或特殊的活動
詞根：occasion
adj. occasional 偶然的；臨時的；特殊場合的
例句：
(1) Try to dress appropriately for each occasion.
試圖為每個場合適當地打扮。
(2) What you said on the occasion was not appropriate.
在這種場合你說這樣的話是不相宜的。
(3) Conversation on such an occasion is not expected to soar above polite commonplaces.
不能指望在這種場合的談話會超越平常的客套。
(4) They go with this occasion. They go with the relationships.
它們出現在這種場合，它們與關系相隨。
(5) I have no occasion to see him these days.
這些天我都沒有機會見到他。
(6) On what occasion do you lie?
在什么場合您會撒謊？
(7) I wish to express my sorrow on this occasion.
我希望能在此場合表達我的哀傷.
(8) Thank you for giving me this opportunity to speak about myself in this special occasion.
非常感謝給我這次機會在這種特殊的場合談論我自己。
(9) This campaign must be the occasion, the vehicle, of your hopes, and your dreams.
這場競選必須成為表達你們的希望和夢想的機會與平臺。