但问题也在于现在出现的问题往往是不知道排出来的是什么。

The question, however, is whether or not they know what's in those emissions.

youdao

但问题也在于现在出现的问题往往是不知道排出来的是什么。

The question, however, is whether or not they know what's in those emissions.

youdao