Other fields of science have also made gigantic strides in progress. Medicine had operated so efficiently in the past half-century that many diseases have been nearly wiped out. And more will join this disappearing group of diseases. Diabetes and polio are under control. We can hope and expect that cancer will be conquered. Certain skin diseases, like psoriasis and eczema, which are exceedingly common though not fatal, will be eradicated. The victims of annoying diseases will lead pleasanter lives.
Even the healthy will benefit from the advances in medicine. Life expectancy already had been lengthened and scientists know that the time is coining rapidly when the person one hundred years old will not be a phenomenon.
Even if the birth rate should remain at its present level, the population will be larger as people stay alive longer. Realizing that the increase of population will Strain natural resources, scientists of all kinds are experimenting with methods for extending these resources.
One matter of immediate urgency will be our source of food. The larger the population, the greater will be the demand for food. Our arable适合工作的) land is already taxed to capacity. Scientists will have to find a way to mass-produce food by hydroponicsthe science of growing vegetables, or other plants, in wateror by irrigating desert wasteland.
This increased demand for food will create an increased demand for water. Certain parts of the United StatesNevada, New Mexico, and Arizona, for examplehave been in desperate need of water for a long time. Periodically, the citizens of New York have been water-rationed because droughts have seriously threatened the water supply in the reservoirs which provide the millions of gallons a day needed in the largest city in the world.
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