在初中物理实验中,玻璃钟罩和抽气机的用处似乎只有演示“真空不能传声”。然而,在教学实践中,笔者经过进一步探索和改进,发现利用玻璃钟罩和抽气机还可以很好地完成以下物理实验,且达到了预期效果。一、用来观察气压降低、液体沸点降低实验在日常教学中,教师在演示液体沸点随气压降低 In junior high school physics experiments, the use of glass bellows and aspirator seems to be the only demonstration of “vacuum can not sound”. However, in teaching practice, after further exploration and improvement, I found that the use of glass bell jar and suction machine can also well accomplish the following physical experiments, and achieved the desired results. First, to observe the pressure drop, the liquid boiling point lower experiment In daily teaching, teachers in the demonstration liquid boiling point decreases with pressure