Beginning of Essay
is rain that is more acidic than normal. is a complicated problem. Caused by air pollution, 's spread and damage involves weather, chemistry, soil, and the life cycles of plants and animals on the land and from in the water. Scientists have discovered that air ....

Middle of Essay
.... and other forms of precipitation containing those mild solutions of sulfuric and nitric acids fall to the earth as . Water moves through every living plant and animal, streams, lakes, and oceans in the hydrologic cycle. In that cycle, water evaporates from the land and sea into the atmosphere. Water in the atmosphere then condenses to form clouds. Clouds release the water back to the earth as rain, snow, or fog. When water droplets form and fall to the earth they pick up particles and chemicals that float in the air. Even clean, unpolluted air has some particles such as dust or pollen. Clean air also contains naturally occurring gases such as carbo ....