The disease develops gradually and imperceptibly.

该疾病难以察觉地逐渐发展着。

Now you have a new friend imperceptibly.

这样，你就不知不觉又多了一个朋友。

Seemed oneself to imperceptibly drop into a scheme inside.

似乎自己不知不觉掉进了一个阴谋里。

Imperceptibly you let my heart, after you let me heartache.

不知不觉你让我心动，后知后觉你让我心痛。

Which from the time of my life occurred imperceptibly change it.

哪时起，我的生活在潜移默化地发生着改变呢。