2021年职称英语考试《综合类》考试共65题，分为单选题。小编每天为您准备了5道每日一练题目（附答案解析），一步一步陪你备考，每一次练习的成功，都会淋漓尽致的反映在分数上。一起加油前行。

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 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.Paragraph l ____【单选题】

A.Life of Macroscopic Bacteria in Livestock\'s Rumen

B.Ways to Reduce Methane\'s 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

正确答案:E

答案解析:本段的第3句点出了“methane\'s heat-trapping power in the atmosphere is 21 times stronger than carbon dioxide. ”

2、Longer Lives Are Happier Lives1 In recent years, scientists have been studying ways to change the body\'s chemistry to reduce the signs and effects of aging.2 0ne group of researchers in Britain has performed experiments on a kind of worm. They have managed to increase the worm\'s normal life span of 20 days by up to 400%. They hope that they will be able to use this research to help humans live longer. However, this is a long way in the future. Another disadvantage is that when (or if) the new technology is successfully developed, it will probably be very expensive. The chance to live longer will only be available to a very few, very rich people.3 Another group of scientists is studying people who have reached a very old age. They believe that this may show what has kept these people healthy and alive for so long. So, if we look at people who have lived into very old age, what do they have in common? Usually they have led a physically active life. This does not mean going to a gym or running ten miles every day. Simple, enjoyable activities like walking seem to be more likely to keep you healthy. Very old people also eat a good, varied diet. Simple foods like vegetable, rice, pasta and fish are the best.4 However, there may be one thing even more important than physical factors like diet and exercise. Research shows that personality, and the way a person thinks, play an important part in how long they will live. People who live into very old age always seem to enjoy life. They have a sense of humor and get satisfaction from simple things. They do not constantly think about the past, but are interested in the present and the future. They do not let life get boring, but have interests and hobbies which keep their minds active and they are open to new ideas. One Japanese man who lived to be 120 commented that the secret of his long life was "not worrying". To express it simply, people who are happy and positive about life are more likely to live longer.5 So, eat well, exercise well, and enjoy life, and you will have a good chance of living to a healthy, happy old age.Paragraph 5 ____【单选题】

A.How to live happy old age

B.Disadvantages of the project

C.The study of old people

D.Personality and other mental factors are more important

E.Worms live longer than humans

F.Live simple lives

正确答案:A

答案解析:这是一个固定句式，祈使句加上and加将来时等于if条件句。只要能做到吃好，锻炼好，享受生活，就会有健康的幸福的晚年。

3、He succeeded because he is both diligent and intelligent.【单选题】

A.ambitious

B.lazy

C.hardworking

D.clever

正确答案:C

答案解析:diligent：勤奋，等于hardworking; ambitious：有志向的；lazy：懒惰的；clever:聪明的。

4、African wild dogFinding a babysitter while you go out to work is, for example, an inconvenience. For the African wild dog, one of the continent\'s most endangered carnivores （食肉动物), it\'s a matter of life and death. A new research shows that once packs (兽群) fall below a certain size, they are not enough animals to both hunt food and stay at home protecting the young.The African wild dog has declined drastically over the past century. Habitual loss (栖息地的丧失), persecution and unexplained outbreaks of disease have all been blamed. Only 3, 000 to5,000 animals remain, and the species is expected to go extinct within decades if the trend continues.Other large carnivores such as the spotted hyena (鬣狗) face similar pressures, yet are not declining. Now Franck Courchamp of Cambridge University has found a reason why. The dog\'s weakness lies in its social organization.Within each pack of up to 20 adults and pups, only the dominant male and female breed. The remaining animals help raise the pups, cooperating to hunt prey and defend the kill from other carnivores.Because pups can\'t keep up on a hunt, large packs leave an adult behind to protect them from predators (捕猎者), which include lions and hyenas. But leaving a babysitter also carries costs. A smaller hunting party is less able to tackle large prey and to defend the kill. There is also one less stomach in which to carry food back to the den, and one more mouth to feed when they get there.Courchamp investigated this awkward trade-off (权衡) by modeling how the costs of a babysitter change with decreasing pack size. This showed that packs of more than five adults should be able to feed all the pups and still spare a babysitter. But with smaller packs, either the hunting or the babysitting suffers, or the animals have to compensate by increasing the number of hunting excursions which itself carries a cost to the pack.Field observations in Zimbabwe supported the model. Packs of five animals or fewer left pups unguarded more frequently than larger packs did. There was also evidence that when they did leave a babysitter, they were forced to hunt more often.A pack which drops below a critical size becomes caught in a vicious circle (恶性循环), says Courchamp, who is now at Paris-Sud University. "Poor reproduction and low survival further reduces pack size, culminating in (最终造成) failure of the whole pack. " And deaths caused by human activity, says Courchamp, may be what reduce pack numbers to below the sustamable threshold. Mammal ecologist Chris Carbone at London\'s Institute of Zoology agrees. Maintaining the integrity of wild dog packs will be vitalin preserving the species, he says.Steps will be taken to protect the African wild dog.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:C

答案解析:文章最后一句话意思是“他说，保持非洲野狗群的完整对保护该物种是重要的”。但文章没有说将采取何种措施保护非洲野狗。

5、My doctor said I should vary my diet more.【单选题】

A.change

B.prepare

C.cook

D.choose

正确答案:A

答案解析:医生说我的饮食要多变化些。本题难度不大，干扰项干扰不大，是送分题，可以确认vary和change都是“变化”的意思，答案是A。