condition,circumstance,situation区别？

*** condition (N) & Vt. (及物动词 transitive verb)

决定;为...的条件
Ability and effort condition success.
成功取决於才干和努力。
使适应;【心】使形成条件反射
使健康;使处於良好状态
Exercise conditions your muscles.

*** circumstance (名词 noun)
情况,环境;情势
In normal circumstances I would have resigned immediately.
在正常情况下,我本会马上辞职的。
事件,事实;(有关)事项
His arrival was a happy circumstance.
他的来到是一件令人高兴的事。
境况;境遇;经济状况
They have been living in reduced circumstances since John lost his job.
约翰失业后,他们一直生活拮据。
细节;详情
The explorer told of his adventure with great circumstance.

*** situation n. (名词 noun)
处境,境遇
He is in a difficult situation.
他处境困难。
形势;情况;局面
The economic situation is now different.
现在经济形势不同了。
地位;(尤指仆役等的)职位,工作
(建筑物等的)位置;地点
The house has a beautiful situation on a hill.
房子座落在小山上,环境优美。
(戏剧,小说等的)紧张情节或场