They also come into contact with bond, a high-grade paper used for important documents.

他们也会接触到铜版纸，一种高级的重要文件用纸。

youdao

They also come into contact with bond, a high-grade paper used for important documents.

他们也会接触到铜版纸，一种高级的重要文件用纸。

youdao