You can change it in the settings on the web page. Just visit www.shanbay.com on your computer and log in.

After changing the word book, it will not take effect until the next day. The words you were already learning will be changed. Will continue to learn, but new words will be added from the new vocabulary book. Therefore, most of the words to be learned the next day are from the previous vocabulary book, and only the new words are from the new vocabulary book. If you are learning a lot of words, there may be no new words the next day, and all the words on the next day will be from the original word book.