2018年职称英语《理工类》概括大意练习（2）2018职称英语考试时间

2018年职称英语理工类概括大意练习（2）2018职称英语考试时间 1.Methane is a colorless,odorless gas； it is also a potent greenhouse gas,and once released into the atmosphere,it absorbs heat radiating from Earths surface. Thats why methane is a major contributor to the plas increasing temperature riseor global warming. Molecule for molecule,methanes 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）,its no surprise that methane released by livestock is one of the chief global 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 Earths atmosphere,which is 78 percent nitrogen and nearly 21 percent oxygen. And without greenhouse gases to trap the suns heat and warm the pla,life was we know it couldnt exist. But in the last 200 years,human activity that requires burning oil,natural gas,and coal for energy has 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 hayyet 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 couldnt live without its microbes. As the microbes digest cellulose,they release methane. The process ours in all animals with a rumen （cows,sheep,and goats,for example）,and it makes them very gassy. Its part of their normal digestion process. When they chew their cud,they regurgitate some food to rechew it,and all this gas es out. the average cow expels 600 liters of methane a day. 6.Thats why we say livestock gas is also a major factor of causing the global warming. 练习： 1.Paragraph 1 _ 2.Paragraph 2 _ 3.Paragraph 4 _ 4.Paragraph 5 _ A. Life of Microscopic Bacteria in Livestocks Rumen B. Ways to Reduce Methanes Heat-trapping Power C. Agriculture Also Contributes to Increased Concentrations of Methane in the Atmosphere D. Why Livestock Releases Methane E. Methane as a Strong Greenhouse Gas F. Livestock as a Prime Factor of the Greenhouse Effect 5.Methane is _ to the intensifying greenhouse effect. 6.Greenhouse gases are indispensable to mankind,but the problem mankind is faced with is _. 7.Generally people heap criticism on _ for the plas temperature rise. 8.Nothing has been mentioned in the passage about _. A one of the major contributors B the ever-increasing atmospheric concentrations of greenhouse gases C big and hefty cows D livestocks normal digestion process E how to cut down the cattle populations F big industries and gas-guzzling vehicles 答案与题解 ： 1. E 本段的第三句点出了 methanes heat-trapping power in the atmosphere is 21 times stronger than carbon dioxide. 2. F 本段要表达的中心意思是： livestock排出的甲烷也是温室效应的一个主要源头。 3. C 本段表达的重点是用 but转折的段后两句。 4. D 本段从科学的角度分析反刍动物为什么会释放出甲烷。 5. A 选 A的依据在第一段的第二句和昀后一句。 6. B 选 B的依据在第三段的第二句、第三句和第四段