职称英语考试《综合类》章节练习题精选
及答案0515-13
1、A Strong Greenhouse Gas1 Methane is a colorless, odorless gas; it is also a potent greenhouse gas, and once released into the atmospheres, it absorbs beat radiating from Earth's surface. That's why methane is a major contributor to the planet's increasing temperature rise or global warming. Molecule for molecule, methane's heat-trapping power in the atmosphere is 21 times stronger than carbon dioxide, the most abundant greenhouse gas.2 With 13 billion cows belching almost constantly around the world (100 million in the U. S. alone), it's no surprise that menace released by livestock is one of the chief sources of the gas. Other prime methane sources: petroleum, drilling, coal mining, solid-waste landfills and wetlands.3 Greenhouse gases like methane and carbon dioxide make up only a small part of Earth's atmosphere, which is 78 percent nitrogen and nearly 21 percent oxygen. And without greenhouse gases to trap the sun's heat and warm the planet, life as we know it couldn't exist. But in the last200 years, human activity that requires burning oil, natural gas, and coal for energy has
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magnified the greenhouse effect.4 Atmospheric concentrations of methane have more than doubled in the last two centuries. Blame for this often focuses on big industries and gas-guzzling vehicles. But agriculture plays a major role, too. In the past 40 years alone, the global cattle population has doubled.5 Cows munch mostly grasses and hay yet they grow big and hefty. Why? Because of the rumen. The rumen holds 160 liters of food and billions of microbes. These microscopic bacteria and protozoa break down cellulose and Fiber into digestible nutrients. A cow couldn't live without its microbes. As the microbes digest cellulose, trey release methane. The process occurs in all animals with a rumen (cows, sheep, and goats, for example), and it makes them very gassy. It's part of their normal digestion process. When they drew their cud, they regurgitate some food to rechew it, and all this gas comes out. The average cow expels 600 liters of methane a day.That's why we say livestock gas is also a major factor of causing the global warming.Greenhouse gases are indispensable to mankind, but the problem mankind is faced with is ____ .【单选题】
A.one of tire major contributors
B.the ever-increasing atmospheric concentration of greenhouse
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gases
C.big and hefty cows
D.livestock's normal digestion process
E.how to cut down the cattle population
F.big industries and gas-guzzling vehicles
正确答案:B
答案解析:选B的依据在第3段的第2句、第3句和第4段的第1句。这三个句子先后介绍了下列观点：没有温室气体，生物不能生存；人类燃烧能源，加剧温室效应；大气甲烷的含量增加一倍。
2、Geology and Heap(1)The importance of particular metals in the human diet has been realized within the past few decades, and the idea that geology might be related to health has been
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recognized for a number of elements such as iodine, zinc and selenium. For example, soils with low iodine contents produce crops, and animals deficient in iodine. A lack of iodine in the human diet leads to some serious diseases.(2)The ultimate source of metals within the human body is rocks, which weather into soil, gaining or losing some of their chemical constituents. The crops we eat selectively remove from the soil the elements that they require for growth. The water we drink contains trace elements leached from rock and soil. Thus the geology and geochemistry of the environment have effects on the chemistry and health of plants, animals and people.(3)So far there is no data to suggest that people living on metal-rich soils experience a potential health hazard. The levels of metals within naturally contaminated soils are generally not high enough to cause serious health problems. Living on metal-rich soils does not represent a health risk unless large quantities of soil are digested or metal-rich dust is inhaled. However, small children are particularly exposed to metal-rich topsoil in playgrounds and gardens. They are also the most likely ones to eat potentially dangerous metal-rich soil.(4)Heavy metals are persistent: they do not break down to other chemicals in the environment. Industrially polluted sites usually undergo intensive clean-up and rehabilitation because heavy metals are a health concern once they enter the food chain. Some trace metals are alleged to
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cause cancer and are also known to cause poisoning(5)In contrast, naturally contaminated soils have not been subject too risk assessment studies and rehabilitation measures, despite the fact that they frequently possess metal concentrations well above those of such polluted by humans and above environmental quality criteria.(6)There is a vital need to understand the potential risks and long-term health effects of living on naturally contaminated soils. Future environmental investigations of naturally polluted soils should concentrate on the potential pathways of metals into the food chain and human body. Geologists should be part of such studies as they can provide the essential background information on rock and soil chemistry as well as the chemical forms of heavy metal pollution.Paragraph 3 ______【单选题】
A.No Evidence to Indicate Bad of Naturally Contaminated Soil
B.Potential Hazards of Human Contaminated Soils
C.Research an Channels of Heavy Metals Getting into Human Food Chain
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职称英语考试《综合类》章节练习题精选及答案0515-13
