imperception

Time slipped by.

时间不知不觉地过去了。

drift into a bush

不知不觉地走进树林

Time crept on.

时间不知不觉地溜走。

Old age creeps up on you before you realize it.

人不知不觉地就变老了.

Summer burst upon us before we realized it.

夏天不知不觉地到来了。

He drifted into errors

他不知不觉地犯了错误。

all at once and unconsciously,

不知不觉地被淹死。

She drifted off into a daydream

她不知不觉地出起神来。

Time goes past unknowingly

时光不知不觉地流逝。

the stealthy approach of old age

不知不觉地进入老年

I felt so much at ease that I found myself speaking.

我觉得毫无拘束，不知不觉地说起话来。

Be careful not to slide into a bad habit.

当心不要不知不觉地就染上坏习惯。

Without forethought or plan.

无意中，不知不觉地没有预想或计划地

So three months glided away.

三个月就这样不知不觉地过去了。

It was as though I was carrying out his advice in spite of myself.

仿佛我在不知不觉地按他的嘱咐办事。

she blushed in his presence; he sensed the presence of danger; he was well behaved in front of company.

他不知不觉地来到了我面前。

Autumn glided into winter.

秋天不知不觉地变成了冬天。

Unwittingly I walked into a bog.

不知不觉地我走进了一个烂泥塘。