发动机气门:"原来"是这样,原来用英文怎么说.

看“原来”是在什么语境了.
如果是动词,表示原来的样子或事物的本来面目,可以用turn out to be,或 prove to be,例如She proved to be a coward,她原来是个胆小鬼（这里是表示惊讶的意思）；He turned out to be a doctor,他原来是个医生（这里是表示最初的状态）；
如果是形容词,可以用original,primary,former等,表示原始的,最初的,之前的意思.
so that is what(how) it is.

原来:
1. formerly
2. originally
3. original
4. former
5. at first

Relative explainations:
<primarily> <aboriginally> <it turns out that> <primitively> <prove>

Examples:
1. 这座建筑原来是打算用作餐厅的。
This building was primarily intended to be a dinning hall.
2. 我认为你原来的计画比这个好.
I prefer your original plan to this one.
3. 这块地毯已经脏得辨认不出原来的颜色了.
The carpet was badly stained, to such an extent that (ie so much that) you couldn't tell its original colour.
4. 她与原来的丈夫离婚十年后又复婚了.
She remarried her former husband ten years after their divorce.
5. 她嫁给一个演员后, 与自己原来的生活环境大不相同, 初时觉得这种生活十分陌生.
Coming from another milieu, she found life as an actor's wife very strange at first.
6. 原来她姑姑就是我表姐.
It turns out that her aunt and my cousin are one and the same (person).
7. 这项任务原来比我们预想的难得多.
The task proved (to be) more difficult than we'd thought.

1 So it is !
2 oh I see !

In fact

So it is.