... Picture Processing, Water-printing Code, Optical Distinguishing, MP3 and 128 Digits Dynamic Coding.Shenzhen Xuezhiyou Technology Co., Ltd ... , reading, repeating, pronunciation correction, following reading, recording and translation from words through paragraphs systematically;6. MP3 function: ... . offering the printing of books 5. adding stealth codes for customers 6. offering recording of books 7. ...