Rainwater is mainly composed of water (chemical component H2O), and a small amount of sulfur dioxide and nitrogen dioxide will form acid rain. In thunderstorm weather, rainwater will contain a small amount of ozone molecules (caused by lightning). There are all kinds of impurities and floating dust in the air. If eaten directly, it will be unclean and cause intestinal infection. And now because of environmental pollution, rainwater acidification, acid rain will not only do great harm to people's skin, but also damage buildings! Of course, it doesn't rain in most areas now! Only some areas!