题目内容
（请给出正确答案）
A、urbanization
B、mining
C、atmospheric deposition
D、chemicals or waste
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（由简答题聘请的专业题库老师提供的解答）
更多“The causes of soil pollution are as follows （).”相关的问题
A、keeps the leaves safe
B、deposits seeds in the soil
C、brings rain and warmth
D、causes sweet buds to open
What can be inferred from paragraph 3 about annual crops and common property lands？
A．They have been part of agriculture for only the past fifty years．
B．They are not considered to be significant causes of soil degradation．
C．They produce more income than perennial crops and private lands do．
D．They may decrease soil fertility and agricultural productivity．
A．The inadequately releasing of treated water into natural water bodies can lead to the degradation of water ecosystem
B．The source of outdoor noise worldwide is mainly caused by machines, transport and transportation systems
C．Air pollution makes people sick, causes breathing problems and even promotes cancer
D．The toxic chemicals that pollute the soil can get into our body when we eat fruits and vegetables that have been grown in polluted soil
What role does heredity play in the life of a plant？
A．It provides the information the plant needs to grow.
B．It helps nutrients move up from the soil into the plant.
C．It causes the seed to swell and burst out of its case.
D．It supplies the energy required to manufacture food.
Mr. Salt wants to create anti-cancer foods by ______.
A．copying tissues from wild plants that take up selenium naturally into crop plants
B．copying genes that causes the plants to take up selenium from the soil
C．moving selenium from the tissues of wild plants into crop plants
D．moving genes from wild plants that take up selenium naturally into crop plants
Mr. Salt wants to create anti-cancer foods by ______.
A．copying tissues from wild plants that take up selenium naturally into crop plants
B．copying genes that causes the plants to take up selenium from the soil
C．moving selenium from the tissues of wild plants into crop plants
D．moving genes from wild plants that take up selenium naturally into crop plants
A．It is natural for mountain lakes to have acidity levels higher than those of other lakes.
B．The harmful effects of increased acidity levels in lakes have been greatly underestimated.
C．Acid rain is found in urban and heavily industrialized regions of the country.
D．There is much disagreement among soil scientists about the causes of acid rain.
E．While plant life remains, acid rain significantly increases the amount of decaying organic matter in natural environments.
Every geologist is familiar with the erosion cycle. No sooner has an area of land been raised alive sea-level than it becomes subject to the erosive forces of nature. The rain beats down on the ground and washed【51】the finer particles, sweeping them into rivulets and then into rivers and out to sea. The frost freezes the rain water in cracks of the rocks and breaks【52】even the hardest of the constituents of the earth's crust. Blocks of rock dislodged at high levels are brought down by the force of gravity. Alternate heating and【53】of bare rock surfaces causes their disintegration. In the dry regions of the world the wind is a powerful force in removing material from one area to another. All this is natural. But nature has also provided certain defensive forces. Bare rock surfaces are in【54】course protected by soil itself dependent initially on the weathering of the rocks. Slowly【55】surely, different types of soil with differing "profiles" evolve the main types depending primarily on the climate. The protective soil covering, once it is formed, is held together by the growth of vegetation. Grass and herbaceous plants,【56】long, branching tenuous roots, hold firmly together the surface particles. The【57】is true with the forest cover. The heaviest tropical down- pours beating on the leave of the giant trees reach the ground only【58】spray, gently watering the surface layers and penetrating along the long passages provided by the roots to the lower levels of the soil. The soil, thus protected by grass, herb, or trees, furnishes a quiet habitat for a myriad varied organisms-earth-worms that importantly modify the soil, bacteria, active in their work of converting【59】leaves and decaying vegetation into humus and food for the growing plants. Chemical action is constantly taking【60】. Soil acids attack mineral particles and salts in solution move from one layer in the soil to another.
(51)
Much of the energy that comes from the sun never reaches the earth's surface. It is either reflected or absorbed by the gases in the upper atmosphere. Of the energy that reaches the lower atmosphere, 30% is reflected by clouds or the earth's surface. The remaining 70% warms the surface of the planet, causes water to evaporate, and provides energy for the water cycle and weather. Only a tiny part, approximately 0.023%, is actually used by green plants to produce food.
Many gases found in the atmosphere actually reflect heat energy escaping from the earth's surface back to the earth. These gases act like the glass of a greenhouse in that they allow energy from the sun to enter but prevent energy form. leaving. They are therefore called greenhouse gases.
When sunlight strikes an object, some of the energy is absorbed and some is reflected. The amount reflected depends on the surface. Dark-colored surfaces, such as dark soil or forest, absorb more energy.
According to the passage, the root cause for weather changes on the earth is
A．the atmosphere surrounding the earth
B．water from oceans and lakes
C．energy from the sun
D．greenhouse gases in the sky
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