俗话说：“没有比较，就没有鉴别。”对比能启发思维，帮助认识。在自然教学中，对于容易混淆的物体、现象和概念，教师根据教材内容的特点，运用对比的方法，揭示它们之间的异同，有利于学生在比较中认识客观事物和建立正确的概念。在教学《沸腾》一课时，学生常常把水沸... As the saying goes: “No comparison, no distinction.” Contrast can inspire thinking, to help recognize. In nature teaching, for the objects, phenomena and concepts that are easy to be confused, the teachers reveal the similarities and differences between them according to the characteristics of the textbooks, and help the students understand the objective things and establish the correct concepts in the comparison. In teaching “boiling” a class, students often boiling water ...