I also made a similar mistake to yours when answering question 21. We both focused too much on the phrase "not detailed enough" and misinterpreted it as referring to the teachers' descriptions, rather than their reasoning. We overlooked the main idea of ​​the paragraph, which emphasized the teachers' lack of in-depth analysis of the causes of classroom events. To avoid similar mistakes in the future, we could summarize the main idea of ​​each paragraph before selecting an answer. This will help us ensure a deeper and more accurate understanding.