《呼吸器官》(人教版十册21课)一课,用两个实验来研究呼出的气体与吸入的气体有什么区别,第一个实验通过石灰水来研究二氧化碳含量的区别,第二个实验通过燃烧的火柴来研究氧气含量的区别。我指导学生实验时,在两个班级分别用了两种方法进行教学。 方法一: 实验一,出示实验装置(学生每人一套)并介绍:广口瓶内盛有澄清的石灰水,瓶塞上有直、弯玻璃管各一根, “Breathing apparatus” (PEP 10book, lesson 21) A course that uses two experiments to study the difference between the exhaled gas and the inhaled gas. The first experiment studied the difference in carbon dioxide content by using lime water. The second Experiment through the burning match to study the difference between the oxygen content. When I instruct students to experiment, I used two methods to teach in two classes respectively. Method One: Experiment One, show the experimental device (a set of students per person) and introduce: The jar filled with clear lime water, there are straight, curved glass tube on each bottle,