Superstar was originally charged, but many universities generally bought its copyright, which means that its books can be downloaded for free in the online libraries of many universities (usually good universities), as long as you have a pass number. But the problem is that the online library of the university is the internal network of the education network, and the external network cannot access it. So what should we do? Fortunately, Superstar has a mobile application called "Mobile Library". You can download. After downloading, click Login in the upper left corner, choose a university, enter your student number and password, and you can download all the books for free! If you are not a student and have no hukou, borrow one from a friend in a famous university. They should not mind. You should know that the download format of the mobile version is pdz format, which can only be read through the superstar e-book client. If you want to convert it into a pdf file for permanent collection, you can refer to my blog (/12458 19728cy), which contains the method of converting PDG and PDZ files into pdf files, and this is the simplest method, which is generally impossible to find, hehe. Anyway, I found this method, which I didn't find online before. After all, Superstar has done a good job in copyright protection.