将要施涂的表面必须完全干净、干燥及无油脂。

Substrate surface must be clean dry and no oil.

youdao

尽管她很费劲地清洗了那个旧坛子，她还是不能使它看起来完全干净。

Although she cleaned the old pot hard, she could not make it look completely clean.

youdao

读书就像是用水不断流过污秽，可能不会完全干净，可是会变得不一样。

Reading is like water blunt uncleanness, it may not clear competetly , but it make dufferences.

youdao

Like a blackboard that's been completely erased, we now have the very same blackboard, and now we start writing new things on it.

就像是被擦干净的黑板一样，我们得到的是完全一样的黑板，重新开始在上面写东西。

耶鲁公开课 - 死亡课程节选