职业考试必备神器,维普考试库官网,维普学堂

Supermarket shoppers have never been more spoilt for choice. But just when we thought traditional systems of selective farming had created the most tempting array of foods money can buy, we are now being presented with the prospect of genetically created strains of cabbages, onion, tomato, potato and apple. It may not tickle the fancy of food purists but it fires the imagination of scientists. Last week they discovered that the classic Parisian mushroom contains just the properties that, when genetically mixed with a wild strain of mushroom from the Sonora desert in California, could help it grow en masse while at the same time providing it with the resilience of the wild strain. 66. ______ "We have found a way of increasing the success rate from one to 90 per cent. " This is just one of the many products that, according to skeptics, are creating a generation of "Frankenfoods" . The first such food that may be consumed on a wide scale is a tomato which has been genetically manipulated so that it does not soften as it ripens. 67. ______ Critics say that the new tomato—which cost $ 25 million to research—is designed to stay on supermarket shelves for longer. It has a ten-day life span. Not surprisingly, every-hungry US is leading the search for these forbidden fruit. By changing the genes of a grapefruit, a grower from Texas has created a sweet, red, thin-skinned grapefruit expected to sell at a premium over its California and Florida competitors. For chip fanatics who want to watch their waist-lines, new high-starch, low-moisture potatoes that absorb less fat when fried have been created, thanks to a gene from intestinal bacteria. The scientists behind such new food argue that genetic engineering is simply an extension of animal and plant breed ing methods and that by broadening the scope of the genetic changes that can be made, sources of food are increased. Accordingly, they argue, this does not inherently lead to foods that are less safe than those developed by conventional techniques. But if desirable genes are swapped irrespective of species barriers, could things spiral out of control? "Knowledge is not toxic, "said Mark Cantley, head of the biotechnology unit at the Organisation for Economic Co-operation and Development, "It has given us a far greater understanding of how living systems work at a molecular level and there is no reason for people to think that scientists and farmers should use that knowledge to do risky things. " Clearly, financial incentive lies behind the development of these bigger, more productive foods. But we may have only ourselves to blame. In the early period of mass food commerce, food varieties were developed by traditional methods of selective breeding to suit the local palate. But as suppliers started to select and preserve plant variants that had larger fruit, consumer expectations rose, leading to the development of the desirable clones. Still, traditionalists and gourmets in Europe are fighting their development. 68. ______ Even in the pre-packaged US, where the slow-softening tomato will soon be reaching supermarkets, 1,500 American chefs have lent their support to the Pure Food Campaign which calls for the international boycott of genetically engineered foods until more is known about the consequences of the technology and reliable controls have been introduced. In the short term, much of the technology remains untested and in the long term the consequences for human biology are unknown. Questions have arisen over whether new proteins in genetically modified food could cause allergies in some people. 69. ______ Then there are the vegetarians who may be consuming animal non-vegetable proteins in what they think is a common tomato, or the practicing Jew who unknowingly consumes a fruit that has been enhanced with a pig's gene. As yet, producers are under no obligation to label "transgeneic" products. Environmentalists worry that new, genetically engineered plants may damage natural environment. A genetically engineered pest-resistant strain of plant that contacts with a native strain, for example, could turn them into virulent weeds beyond chemical control. Animal welfare groups worry about the quality of life of farm animals manipulated so that they produce more meat, milk, and eggs but which may suffer physical damage in the process. 70. ______ Many of these fears spring from ignorance. And although it is hard to separate the paranoia from the benefits, the fact remains that genetic engineering offers ways of solving serious medical and agricultural problems. A. Western farmers have already bred cattle with more muscle than a skeleton can carry. B. Supporters say the tomato, unsurprisingly called Flavr Savr, will taste better because it will be able to nature on the branch longer. C. Consumer opposition means that there are genetically manipulated foods on the German markets, and the Norwegian government has recently put research into genetically engineered foods on hold. D. For example, if a corn gene is introduced into a wheat gene for pest resistance, will those who are allergic to corn then be allergic to wheat? E. "Mushrooms in the past were almost impossible to cross, "says Philippe Callac, one of the three scientists working on the mushroom. F. Genetic engineering will interfere with the balance of nature.

1544人做过

【简答题】

Some people claim that staying in a place all one's life is good for one's growth, while others disagree with the view, and they prefer changing the place. Write an article to express your point of view on this topic. You should write no less than 250 words. Write your article on ANSWER SHEET 2.

1542人做过

【组合题】

1538人做过

【组合题】

In last two years the world has seen an intensification (53) ______.in the search for sustainable development and social (54) ______.responsible business. A series of events, from demonstrationsat the WTO meetings in Seattle expressing dissatisfactionfor the effects of economic globalization, the terrorist attacks (55) ______.on the WTO in New York on "9ﾷ11", corporate financialscandals such as Enron, WorldCom and Ahold, the collapse (56) ______.of He Argentinean economy and the Internet bubble, haveextended this search from wastern social and environmental circles to mainstream economic and business circles acrossthe globe. According to Hazel Henderson, a leading thinkeron economics and development, the traditional economic (57) ______.profession is in a state of crisis. We witness such impoverishing (58) ______.of millions in Thailand, Indonesia and the other "tiger economies"during the Asian meltdown, as well as in Russia, Mexico, Brazil,and Argentina. Too often, luring people from their traditionalways and communities into monetarized urban areas hasproved unsustainably and led to such human tragedies. (59) ______.This criticism is recognized by an increasing number of mainstreameconomists, who are "defecting" their orthodoxies. They are helpingexpand the horizons of the economics profession toward a moremodest, inclusive and inter-disciplinary stance. Leading universitiesand institutes like the World Bank are stepping up research (60) ______.on alternate development indicators, accounting for "softer" (61) ______.values such as environment, social values and general well beingof the society with a long term time horizon. These efforts reflectmuch of that the notion of Gross National Happiness is all about. (62) _____.In response to the scandals in corporate governance and the increasedcall for truly responsible business leadership, the western businesscommunity is also exploring alternatives.

1537人做过

【组合题】

Saturn For beauty and interest alike, there are few objects in the starry heavens to compare with Saturn. This magnificent planet, with the system of rings that encircles it, provides an unforgettable spectacle when it is viewed through a powerful telescope. The Saturnian system includes not only the planet and its rings, but also 11 or more satellites, or moons. To the ancients Saturn appeared to be the most insignificant of the heavenly bodies that were supposed to circle the Earth (the Sun, the Moon, Mercury, Venus, Mars, Jupiter, and Saturn) , as distinguished from the fixed stars. The glorious rings that surround the planet were invisible before the invention of the telescope in the first decade of the seventeenth century. Otherwise this magnificent crown might have saved Saturn from the sinister reputation that it once bore. Ancient astrologers maintained that it had a sinister influence upon people. Saturn is far from the center of the solar system. The mean distance of Saturn from the sun is 1,428,000,000 kilometers, or about 9.5 times the distance of the earth from the sun. The density of Saturn is very low, much lower than that of any other planet. In fact it is only about three-quarters that of water. Because of this fact some astronomers hold that Saturn is far from having reached the solid condition. Venus The beautiful white planet whose orbit lies between those of Mercury and of the Earth is called Venus after the Roman goddess of beauty. The planet is similar to our earth in size and mass. Its diameter is about 12,100 kilometers; the earth''s is 12,725 kilometers. Its mass is a little more than four-fifths that of the earth. Its density is about nine-tenths that of our planet. Venus revolves around the sun once every 225 days in an orbit that is very nearly circular. As the planet revolves, it rotates about its axis once every 243. 1 earth days, from east to west instead of in the west-to-east direction of most other celestial bodies. The planet is tilted only slightly with respect to the plane of its orbit. As it proceeds -along its orbit, Venus is sometimes on the far side of the sun from the earth, or at superior conjunction. At other times Venus is between the sun and the earth, at inferior conjunction. At superior conjunction it is quite far from earth. But at inferior conjunction it is only about 41, 840,000 kilometers away-closer than any other planet. These variations in distance result in notable differences in the apparent size of the planet as viewed from the earth, at inferior conjunction, the apparent diameter is six times greater than at superior conjunction. Venus has been explored by 15 spacecraft of which five were from the United States and ten were from the soviet Union. Some of these were orbiters, some were landers, and some were both. The planet is completely covered with opaque clouds, which make an almost perfect reflecting layer. Mercury Mercury is the nearest of the planets to the sun. It is the smallest of all and also, at certain intervals, one of the brightest. In spite of that fact, it is generally not easy to see with the naked eye. For one thing, it appears in the heavens only during the hours of twilight and dawn, when even very bright stars do not appear at their best. Besides, it is often obscured by haze near the horizon. The great Polish astronomer Nicholas Copernicus once lamented the fact that he had not been able to see Mercury at all in his many years of observation of the heavens. Perhaps this was due to the nature of the district where he lived — the low and misty region of eastern Prussia where the Vistula flows into the Baltic. Mercury makes such a small circuit around the Sun that it is always comparatively near that body. It never rises in the morning or sets in the evening much before or after the Sun. Because of its appearance sometimes in the east and sometimes in the west, some ancient peoples including the Egyptians, Hindus, and Greeks,- thought of it as two separate heavenly bodies — a morning star and an evening star. The Greeks called the morning star "Apollon" after the god of the sun, and the evening star "Hermes" , the name of the swift messenger of the gods, because the planet''s apparent motion among the stars was so swift. It is said that the Greek philosopher Pythagoras, who lived in the sixth century B. C. , was the first to recognize that the morning star and evening star were one and the same heavenly body. That fact was well known to Roman astronomers. Hermes was worshiped by the Romans under the name of Mercury. Scientists were surprised to discover that Mercury has a very thin atmosphere consisting of helium. It is so thin that the word "atmosphere" gives the wrong impression, but no such gas envelope has been expected at all. Another surprise was that Mercury has a weak magnetic field. Whether this field is produced by the planet itself or produced in some way by the solar wind — the stream of particles flowing out from the Sun — is not yet certain. But at any rate, the interior of Mercury is probably earth like in composition, with an iron core and a less dense outer crust.

1536人做过

【组合题】

Aging baby boomers are determined to fight the aging process. They spend millions of dollars a year on (31) they perceive as the best anti-aging products (32) can buy. They are being very short-sighted (33) their quest for youth. Just (34) a well-maintained car eventually breaks (35) , our bodies (36) the same. Aging is a chronic and ongoing condition we all face. Successful aging requires planning. The baby boomer generation has made (37) loud and clear that they want to remain in their homes and communities (38) they age. Yet they (39) the most important factor that will help them achieve the goal (40) age successfully at home. The home environment most boomers reside in was built for the young family. A young body (41) run the stairs, stand at the sink and get on a stool to (42) things. These are activities that become difficult or even (43) for some as they age. Falls are the number one robber of independence of the aging body. Yes, all the exercise and good nutrition cannot (44) one from falling and breaking a bone. Eventually the body slows down and (45) mobile can be an issue. It becomes hard to get into the bathroom. Many aging seniors stop taking baths because of a (46) of falling. No matter how hard we want to stay young or our bodies (47) maintain a youthful appearance, eventually we will slow down. So what is the best investment for successful aging at home? It is simple. Adjust your present living environment to meet the needs of your aging body. Many aging seniors (48) up in nursing homes or assisted living (49) their home environment could not (50) their needs.

1534人做过

【简答题】

One day in the dead of winter, I looked out my back window and saw a chicken. It was jet-black with a crimson wattle, and it seemed unaware that it was in New York City. In classic barnyard fashion, It was scratching, pecking and clucking. I shrugged off the apparition. Birds come and go. Usually they're pigeons, not chickens, but like other birds, this one had wings and it would probably use them. Or so I thought. The protagonist of this story is known simply as the chicken. How it came to a small backyard here, remains a matter of conjecture. The chicken made its first appearance next door, at the home of a multitude of cabdrivers from Bangladesh. My wife, Nancy, and I figured they had bought the chicken and were fattening it for a feast. That hypothesis fell into doubt when the chicken hopped the fence and began pacing the perimeter of our yard with a proprietary air. Eating it was out of the question. As a restaurant critic and an animal lover, I subscribe to a policy of complete hypocrisy. Serve fish or fowl to me, but don't ask me to watch the killing. Once I meet it, I don't want to eat it. Nancy and I next theorized that the chicken had escaped from a live-poultry market about four blocks away and was on the run. Our hearts went out to the brave little refugee. We had to save it.

1534人做过

10.

【组合题】

1533人做过