《呼吸器官》的实验2,采用“吹气排水”的方法、证明人在呼吸时呼出的是二氧化碳。学生在实验时,往往出现把燃烧的火柴伸入广口瓶后,要经过4、5秒钟火柴才会熄灭的现象,这样就不能很好地体现实验效果。要做到把燃烧的火柴放入广口瓶,火焰马上就会熄灭,关键的是在实验的过程要把握好吹气的方法。 具体的吹气方法是: 1.排空口腔内的气体。 “Respiratory organs” experiment 2, the use of “inflatable drainage” method to prove that people breathe in the breath of carbon dioxide. Students in the experiment, often appear after the burning match into the jar, to go through the phenomenon of the match will not extinguish 4,5 seconds, so you can not reflect the experimental results well. To do the burning of matches into the jar, the flame will be extinguished immediately, the key is to experiment in the process of blowing to grasp the good way. The specific method of insufflation: 1. Empty the gas inside the mouth.