陆地和海洋表面的水蒸发变成水蒸气,上升到一定高度之后遇冷液化成水滴,当它大到上升气流托不住的时候,就从云中落了下来,形成雨。雨的表现形态多样,对人体的影响也不同。有害的酸雨酸雨是一种溶入酸性物质的雨,当雨水的PH值小于5.6时,就是酸雨。随着工业的发展,人类向大气中排放的硫氧化物和氮氧化物越来越多,酸雨也就成了全球性的共同问题。早在20年前,西德的《明镜》周刊 The water on the surface of the land and the sea evaporates into water vapor and rises to a certain height and then liquefies into water droplets, which fall from the clouds and form a rain when it is so large as to ascend. Rain manifests itself in diverse forms and has different effects on the human body. Harmful Acid Rain Acid Rain is a rainwater that dissolves in acidic materials. When the PH of rainwater is less than 5.6, it is acid rain. With the development of industry, more and more sulfur oxides and nitrogen oxides have been released into the atmosphere by human beings, and acid rain has also become a common global problem. As early as 20 years ago, West Germany’s “Der Spiegel” magazine