Zhao Quyang, Class 5 (3) Counselor of Jinhua New Century School: I bought a bottle of Coca-Cola when Wang Yanru came home at the weekend. I couldn't wait to open the bottle cap because I was too hot and thirsty. With a bang, I saw glistening foam coming out of the soda and flowing to the bottle mouth, which scared me. When the foam was about to gush out from the bottle mouth, I used my quick wits and put the bottle cap on the bottle mouth, so the foam had to "run down quickly" That was close! Almost sprayed me in the face! Recalling the scene just now, I opened the bottle cap again, and now there are not so many bubbles, so I took a sip with confidence. I looked at this bottle of coke and couldn't help wondering-why does coke bubble immediately after opening it? Is it related to the thermal expansion and cold contraction of liquid? I thought about it, but I couldn't think of a clue. I just thought of a correct answer-"Because cola is a liquid, it will bubble, which means there is gas in it, so this phenomenon may be related to the expansion and contraction of gas and liquid." Right? I'm going to go online and search for the answer to this "unsolved mystery". Open "Baidu" to check, hey! There is an answer! "Baidu knows" reads-"Before the coke bottle was opened, the bottle was in a high-pressure environment. After opening the lid, the pressure becomes lower, which leads to the decomposition of carbonic acid. The decomposition products are water and carbon dioxide, and the gas is carbon dioxide. Under the same mass, the volume of gas is much larger than that of liquid, so under the action of pressure, even bubbles may be produced. It can be seen that the foaming of cola has nothing to do with the expansion and contraction of liquid. " Oh! So that's what happened! I heard from the science teacher that there is air pressure in coke, so "air pressure" means "pressure"! Now I finally understand that the problem of "why does coke steam as soon as it is opened" has been solved and is no longer an "unsolved mystery" in my heart. Later, we encountered such a topic in scientific practice: "The following phenomena are related to the thermal expansion of liquid and gas and the contraction of gas due to cold: a. Open the bottle cap of cola and gas gushes out from the bottle mouth; B, the hot air balloon is launched; C, the air is compressed ". At that time, many students in our class chose the wrong A, only me and several other students chose the right B! Won the praise of teacher Wang! Through this little exploration, I not only deeply understand a scientific truth, but also gain some experience: in daily life, there are many strange problems that are puzzling. There must be some conclusions and answers behind these strange questions. Those who have explored these conclusions must have told themselves: Ask more questions, learn more and think more when you encounter problems that you can't! When you encounter problems that can't be solved, do you "study more and think more" like me?