If students don't have a desire to learn, all our plans, all explorations and theories will fall through." "Thinking begins with problems, and the design of appropriate questions stimulates students' desire to explore and makes their thinking active. To improve the effectiveness of questioning, because effective questions are the beginning of classroom dialogue, can arouse students' thinking, interest sparks. The effectiveness of the problem in one to have a certain degree of openness, two to have a certain degree of depth, three should pay attention to the level of students, to make different levels of students have a thinking interest, thinking space.