Book 1: CET-4 true questions/CET-6 true questions
If you have a good English foundation, NMET English 120+, I recommend you to use the book Spark. Although there are few explanations, mainly relying on video lessons, for students with good English foundation, the focus is on improving oral English and brushing questions. If your English foundation is average or even poor, NMET English 120-, I suggest starting with the book Juwei (intensive reading of CET-4). Original text, translation, key content identification, problem-solving methods, problem-solving skills.
The second book: Ten days to get CET-4 vocabulary/Ten days to get CET-6 vocabulary, with emphasis on orange vocabulary. Level 4 1900, level 6 1500, that's the most important. Written by Mr. Jiang Tao and Mr. Wang Miaoran, the chief lecturers of New Oriental English Vocabulary Band 4 and Band 6.
Book 3: Recommend a copybook "High Score of CET-4 Writing and Translation"/"High Score of CET-6 Writing and Translation". Also written by Jiang Tao, there are ten wonderful model essays on writing and translation in CET-4. There is a hidden rule when marking papers, for example, poor writing affects understanding and lowers the score by one grade. There are five levels of writing in CET-4 and CET-6, each with 20 points, so if you are not good at writing, 20 points will be deducted for writing translation, and 20 points will be added if you write too much. Practice writing 10 minutes every day for one month, and increase writing and translation by 20 points each.
The fourth book is writing prediction, which is usually published in April every year.
In fact, the greater success still depends on your down-to-earth efforts, and books and materials are icing on the cake. Only what suits you is the best, and everyone should recognize their own position.