Food Fright
Experiments under way in several labs aim to create beneficial types of genetically modified foods, including starchier potatoes and caffeine-free coffee beans. Genetic engineers are even trying to transfer genes from a cold-winter 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 Sansonis 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 butterfly 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 todays 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 food 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?
1. Paragraphs 1,23 tries to give the idea that
A) GM foods may bring about great benefits to humans.
B) We cannot recognize the benefits of GM foods too early.
C) GM foods may have both benefits and harm.
D) GM foods are particularly good to the kwashiorkor patients.
2. Why is the case of the pollen-sprayed milkweed citied in Paragraph 6?
A) It is cited to show GM foods can kill insects effectively.
B) It is cited to show GM foods contain more protein.
C) It is cited to show GM foods also have a dark side.
D) It is cited to show GM foods may harm crops.
3. What happens to those insects when not killed by the spray of insecticide?
A) They may lose their ability to produce offspring.
B) They may have a higher ability to adapt to the environment.
C) They move to other fields free from insecticide.
D) They never eat again those plants containing insecticide.
4. Which of the following statements concerning banning GM foods is true according to the passage?
A) Underdeveloped countries have banned GM foods.
B) Both Europe and the U.S. have banned GM foods.
C) Most European countries have not banned GM foods.
D) The United States has not banned GM foods.
5. What is the writers attitude to GM foods?
A) We cannot tell from the passage.
B) He thinks their benefits outweigh their risks.
C) He thinks their risks outweigh their benefits.
D) He thinks their benefits and risks are balanced.
答案: ACBDA
以let开头的祈使句用法归纳
祈使句如何变为否定句
感叹句的基本句型
几种特殊情况的反意问句
反意问句的主语有何要求
反意疑问句的基本结构和特点
陈述句是复合句的反意疑问句
有关反意疑问句的几个学习难点
如何引用祈使句
祈使句如何变为反意疑问句
感叹句后接附加疑问句
祈使句用法详解:表建议
由as if引出的感叹句中
是考查祈使句还是非谓语动词
祈使句用法详解:表祝愿
祈使句用法详解:表邀请
“be+形容词”用于祈使句
当陈述部分有情态动词时如何变反意问句
若陈述部分有Let’s / Let us如何构成反意问句
陈述句改为感叹句
不要混淆祈使句与非谓语动词
祈使句用法详解:表叮嘱
对特定的人使用的祈使句
感叹句变为间接引语
祈使句用法详解:表禁止
用复合不定代词作主语的祈使句
当陈述句中含must的时如何变反意疑句
感叹句如何变为间接引语
祈使句用法详解:表厌烦或为耐烦
祈使句用法详解:表指引
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