题目内容：
Development and the Protection of Environment Modern technology has developed in a manner which often conflicts with the environment. The many industrial pollutants constantly impact the environment in a harmful way. Nevertheless, it is possible and practical to achieve a high level of technology, with- out altering the overall natural environment. There are two basic methods of conserving the natural environment. One is alternative technology in which techniques (such as windmills and solar energy) must be found for providing power. The other is to try to minimize the, effects of modern technology by the more efficient: use of materials and more, effective pollution control.There comes a point when the quality of life can no longer be, improved because of the high population density and the largely unsuccessful attempts to meet its demands.
Present energy policies of the western world are considering new energy sources to meet the demands of a growing population. The main Sources used have been oil, gas, and coal-which are in limited supply-- and nuclear power, which has problems concerning radioactive waste storage. Wind and solar energy are alternative possibilities, but only solar energy is likely to become a main power source for many countries.
Many of the materials used daily in a technological society are destined to be discarded, Rags, paper, metal, glass, and plastics are all substances that could be recycled or reuseD．Research is being done to determine methods of separating useful products from industrial and domestic waste.
The processing of sewage is also helpful. This is collected in gasholders and burned to produce heat and create electricity. The waste itself is often used for soil enrichment.Modern technology is harmful to the natural environment mainly because A．of industrial pollutants
B．it has become too expensive
C．it has become too complicated
D．it consumes all natural resources
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