Questioning and asking difficult questions is an important manifestation of students' autonomous learning. To optimize the classroom structure and activate students' subjective consciousness, students must be encouraged to question and ask difficult questions. Teachers should create a harmonious and unified classroom atmosphere and allow students to "interrupt", ask questions, argue and even put forward different views from teachers at any time. Students have questions and ask difficult questions, which is a valuable performance of serious thinking, independent learning and active exploration, and deserves teachers' enthusiastic encouragement and praise. At present, students should be welcomed and encouraged to "interrupt" at any time, ask all kinds of difficult questions and give correct explanations.