Questions 18 to 20 are based on the-我要搜题网

[不定项选择题]共用题干 Food Fright
Experiments under way in several labs aim to create beneficial types of genetically modified(GM)foods,including starchier potatoes and caffeine-free coffee beans.Genetic engineers are even trying to transfer genes from a cold-water fish to make a frost-resistant tomato.A low-sugar GM strawberry now in the works might one day allow people with health problems such as diabetes to enjoy the little delicious red fruits again.GM beans and grains supercharged with protein might help people at risk of developing kwashiorkor. Kwashiorkor,a disease caused by severe lack of protein,is common in parts of the world where there are severe food shortages.
Commenting on GM foods,Jonathon Jones,a British researcher,said,"The future benefits will be enormous,and the best is yet to come."
To some people,GM foods are no different from unmodified foods."A tomato is a tomato," said Brian Sansoni,an American food manufacturer.
Critics of GM foods challenge Sansoni's opinion.They worry about the harm that GM crops might do to people,other animals,and plants.
In a recent lab study conducted at Cornell University,scientists tested pollen made by Bt corn,which makes up one-fourth of the U .S.corn crop.The scientist sprinkled the pollen onto milkweed,a plant that makes a milky juice and is the only known food source of the monarch but-terfly caterpillar. Within four days of munching on the milkweed leaves,almost half of a test group of caterpillars had died."Monarchs are considered to be a flagship species for conservation,"said Cornell researcher Linda Raynor."This is a warning bell."
Some insects that are not killed by GM foods might find themselves made stronger. How so? The insecticides used to protect most of today's crops are sprayed on the crops when needed and decay quickly in the environment.But GM plants produce a continuous level of insecticide.Insect species feeding on those crops may develop resistance to the plants and could do so in a hurry, say the critics.Insects may also develop a resistance to the insecticide Bt.
At the forum on GM food held last year in Canada,GM crops that have been made resistant to the herbicide might crossbreed with wild plants,creating"superweeds"that could take over whole fields.
So where do you stand?Should GM foods be banned in the United States,as they are in parts of Europe?Or do their benefits outweigh any of the risks they might carry? Paragraphs 1,2&3 try to give the idea that______.
A.GM foods are particularly good to the kwashiorkor patients
B.GM foods may have both benefits and harm
C.we cannot recognize the benefits of GM foods too early
D.GM foods may bring about great benefits to humans

[单项选择]Questions 18 to 20 are based on the following passage.You can find in the first room the following EXCEPTA. dictionaries.B. bibliographies.C. telephone books.D. literature works.

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[单项选择]Questions 18 to 20 are based on the following passage.
You can find in the first room the following EXCEPT
A. dictionaries.
B. bibliographies.
C. telephone books.
D. literature works.