the reason for （doing）sth……的原因（理由）
注意：英语里并不存在the reason of （doing）sth改错题和完形填空常考这个点。下面通过经典例句研习，以期达到融会贯通，灵活运用：
People must have a reason for saying such things.
人们这么说一定是有原因的。
By common consent their talk avoided the reason for their being there at all
双方达成共识，他们的谈话对他们去那儿的原因完全避而不谈。
To an extent, that is the reason for the meeting.
在某种程度上，那就是召开这次会议的原因。
The reason for the flood was all that heavy rain.
造成洪水的原因全是那场大雨。
What is the reason for your absence yesterday?
你昨天缺席的原因是什么？
What is the reason for the game's enduring appeal?
这种游戏为什么具有经久不衰的吸引力呢？
Detectives are so far at a loss to explain the reason for his death.
至今侦探仍茫然无法解释他的死因。
The reason for his success is his hard work and determination.
他成功的原因是他的努力和决心。
Ryle explained the reason for his sudden return to London.
赖尔解释了他突然返回伦敦的原因。
She hoped he hadn't deduced the reason for her visit.
她希望他还没有推断出她此次来访的原因。
I think I've sussed the reason for it.
我想我已经弄清楚其中的缘由了。
suss/sʌs/ v.发现;意识到;认识到 n.嫌疑犯;某种特有的知识
It's only fair that you tell us the reason for your resignation.
你告诉我们你辞职的原因才是公平的。
Whatever the reason for our like or dislike, snakes do something good in the circle of life.
不管我们出于何种原因喜欢或讨厌蛇，这种动物还是在生命循环中起到了一些有益作用。
中考真题- 2015 沈阳
The reason for the explosion is not that people have been reproducing like rabbits, but that people have stopped dropping dead like flies ．
人口爆炸的原因不是人们像兔子一样繁殖,而是人们不再像苍蝇一样死去。
高考真题- 2017 江苏
Every animal sleeps, but the reason for this has remained foggy ．
所有动物都会睡觉，但我们还不清楚其中的原理。
高考真题- 2017 北京