Pirated books are generally divided into two types, one is remake and the other is photocopying. There are many typos in the rearrangement, and they are very different from the original ones; Photocopy: Look at the head of the whole book. If it is seriously uneven or even tilted, and the words look blurred, it must be photocopied.

Moreover, pirated books rarely use paper and cover technology, and the cover paper is relatively thin and soft.