1. Insufficient vocabulary: CET-4 requires mastering about 4,500 words, which is a challenge for many college students. They may have learned some basic vocabulary in school, but it is difficult to use it flexibly in practical application. In addition, vocabulary questions in CET-4 often involve some uncommon words and phrases, which also brings great trouble to candidates.

2. Insufficient reading comprehension: The reading comprehension part of Band 4 usually includes three articles, each of which is followed by a main topic. These articles cover a wide range of topics, including social, cultural, scientific and technical aspects. For many college students, it is very difficult to accurately understand the meaning of the article and answer questions in a limited time.

3. Insufficient listening comprehension: The listening part of Band 4 consists of four sections, each with 10 questions. These topics mainly test candidates' ability to understand spoken English. However, due to the lack of practice at ordinary times, many college students are weak in listening, and it is difficult to accurately understand what they are listening to in a short time.

4. Lack of writing ability: The writing part of CET-4 requires candidates to write a short essay within 30 minutes. This is a great challenge for many college students, because they may seldom practice English writing and lack writing skills and experience.

5. Difficulty in time management: The total duration of CET-4 is125min, including listening, reading, writing and translation. Because the difficulty of each part is different, candidates need to allocate time reasonably to complete each part of the topic. However, many college students often can't manage their time effectively during the exam, which leads to some unfinished parts or low quality answers.