(The vocabulary requirement for Kaobo English is 8000-10000. Many people are confused when they see this number. To be honest, I thought so too at the beginning, but when I really wrote down all these words, the sense of accomplishment that followed was not the slightest bit. I didn't buy a vocabulary book at the time, but memorized words through real questions. Because in a specific language environment, memorizing words is not isolated, so it is not easy to forget. Fortunately, I bought the book "Ten Thousand Cases of Kaobo English Vocabulary", which contains very detailed notes on English vocabulary, so I don't need to use a dictionary to look up the meaning of words, which saves a lot of time.)