Copies of the original mill certificates are retained for future reference.

的原厂证书复印件留存备查。

These must be either original mill certificates or "wet stamped" by responsible person as being true copies.

这些必须是出厂材料单原件或责任人签章的真实有效副本。

A lot of people are still ignorant of the advances online education has made in recent years and fail to recognize the difference between legitimate degrees and "diploma mill" certificates.

很多人还是忽视这几年网上教学取得的进步，并且对正规的学位和“文凭制造厂”的证书无法区分。