opportunity

opportunity cost

[经] 时机代价, 机会成本

opportunity cost principle

[经] 机会成本的原则

opportunity cost value

[经] 机会成本价值

Opportunity knocks only once

机不可失,时不再来

opportunity line

[经] 机会线

Opportunity makes the thief

疏忽招致盗贼

opportunity shop

义卖商店（为慈善事业募资）