This series of textbooks contains the core vocabulary of HSK for foreign students to study and apply in their daily activities and to prepare for the HSK test. Through the use of these textbooks, students are able to master 3000 words within one year, and will also allow them to fulfill the requirements for the intermediate level of HSK and above. The words to be studied daily range from the simple to the complex, and become more difficult as study progresses. Different levels of HSK words (level A, B, C, D) are included in the study. The books also add classifications, exercises and detailed English annotations. It also details the key or difficult points of the HSK test.