Notes

the continuous movement of water between the Earth's surface and the atmosphere(hydrological cycle)
pollutes water sources by dumping wastes in rivers, streams, and oceans(industry)
the leading cause of water contamination in countries without water treatment plants(sewage)
a source of water pollution caused by the overuse of pesticides and fertilizers(agriculture)
caused by an overabundance of organic matter in water supplies(eutrophication)
the decomposition of organic matter by microorganisms(putrefaction)
a chemical pollutant that can enter the water cycle through agricultural or domestic use(pesticides)
can cause the contamination of underground water supplies if poured on the ground(petroleum)
a metal that leaks into water supplies via the soil or aging water systems(lead)

How was Theodore Roosevelt's approach to the environment different from that of modern-day environmentalists?
Theodore Roosevelt's approach to the environment was different because he didn't believe that nature should be preserved for nature's sake; he just wanted to save it for future generations.

Why did Roosevelt set aside millions of acres for national parks and wildlife?
He set aside millions of acres for national parks and wildlife so future generations can live sustainably, with the resources.
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Similar types of breeding and pollination experiments are being performed in attempts to improve agricultural products. New breeds of hybrid corn, wheat, rice, and other crops are now available to give greater yields per acre as well as better nutritional value. One of the major nutritional problems in the world is the unavailability of adequate protein in the diet. In general, plant protein is low quality protein because they are short some of the amino acids essential for human growth and development. New corn varieties being developed by geneticists offer great promise in reducing the world protein deficiency problem.