课堂教学是一个动态的、随机生成的过程。课堂上,教师与学生的心态在变化,学生知识经验的积累状况在变化,课堂的物理环境也在变化。面对这样充满不确定性的课堂,学生一些发人深思的问题、富有个性的理解和表达随时可能不期而至,超出教师的意料。而这些无法预料的新想法,往往会成为教学发展的契机,乃至整节课的一个精彩亮点!这就要求教师要善于把握教学 Classroom teaching is a dynamic, randomly generated process. In the classroom, the mentality of teachers and students is changing, the accumulation of students’ knowledge and experience is changing, and the physical environment of the classroom is also changing. Faced with such a classroom full of uncertainty, some of the students thought-provoking questions, personalized understanding and expression may unexpected at any time, beyond the teacher’s expectations. And these unexpected new ideas, often become an opportunity for teaching and development, and even a highlight of the whole class! This requires teachers to be good at grasping teaching