核心词汇 (Target Vocabulary)

学习 3B 核心词汇，掌握转基因与现代农业前沿表达，点击语音按钮可听纯正美音发音。

allergic [əˈlɜːdʒɪk] adj.
Having an allergy to something; caused by an allergy.
过敏的；由过敏引起的
"Critics worry that inserting Brazil nut genes into soybeans could trigger unexpected allergic reactions in consumers."
alternative [ɔːlˈtɜːnətɪv] n./adj.
Something that is different from the usual, or can be chosen instead of something else.
可供选择的事物；替代的
"Organic farming offers consumers an alternative to genetically engineered supermarket produce."
conventional [kənˈvenʃənl] adj.
Traditional and ordinary; following accepted rules or standards.
常规的；传统的
"Conventional plant breeders have altered crop genetics for millennia by crossing related species."
deficiency [dɪˈfɪʃnsi] n.
A state of not having, or not having enough, of something that is needed.
缺乏；不足；缺陷
"Vitamin A deficiency causes between 250,000 and 500,000 children to go blind every single year."
diminish [dɪˈmɪnɪʃ] v.
To reduce or be reduced in size, importance, or extent.
减少；降低；减弱
"By engineering pest-resistant cotton plants, farmers dramatically diminish their reliance on chemical sprays."
modify [ˈmɒdɪfaɪ] v.
To change something slightly, especially in order to improve it or make it more acceptable.
修改；改变；基因改造
"Biotechnologists modify the genetic sequence of corn to produce its own internal natural pesticide."
notwithstanding [ˌnɒtwɪθˈstændɪŋ] prep./adv.
Despite the fact or thing mentioned; in spite of.
尽管；虽然
"Fears and controversies notwithstanding, proven examples of harmful effects from approved GE crops remain rare."
nutritional [njuːˈtrɪʃənl] adj.
Relating to the substances in food that help you stay healthy and grow.
营养的；滋养的
"Golden rice was engineered with daffodil genes to significantly enhance its nutritional value."
revolution [ˌrevəˈluːʃn] n.
A very important change in the way that people do things, or a complete cycle of transformation.
重大变革；革命
"The manipulation of plant DNA is producing a profound revolution in global agriculture."
trait [treɪt] n.
A particular characteristic, quality, or tendency that someone or something has.
特征；特质；性状
"Farmers select for desirable traits like drought resistance, high yield, and rapid seedling growth."
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The Battle for Biotech

生物科技之争：转基因作物利弊权衡与未来粮食安全

Paragraph A
What exactly are biotech foods? Biotech foods are produced from animals and plants that have been genetically altered. Genetic alteration is nothing new. Humans have been altering the genetic traits of plants for thousands of years, by keeping seeds from the best crops and planting them the following years, and by breeding varieties to make them taste sweeter, grow bigger, or last longer. In this way, we've transformed the wild tomato from a fruit the size of a small stone to the giant ones we have today. On the other hand, the techniques of genetic engineering are new and different. Conventional breeders always used plants or animals that were related or genetically similar. In so-doing, they transferred tens of thousands of genes. In contrast, today's genetic engineers can transfer just a few genes at a time between species that are distantly related or not related at all. There are surprising examples. Rat genes have been inserted into lettuce plants to make a plant that produces vitamin C.
Paragraph B
Moth genes have been inserted into apple trees to add disease resistance. The purpose of conventional and modern techniques is the same to insert genes from an organism that carries a desired trait into one that does not. Several dozen biotech food crops are currently on the market, among them varieties of corn, soybeans, and cotton. Most of these crops are engineered to help farmers deal with common farming problems such as weeds, insects, and disease.
Paragraph C
Are biotech foods safe for humans? As far as we know, so far, problems have been few. In fact, according to a 2016 report from the National Academy of Sciences in the United States, no differences have been found that indicate a higher risk to human health and safety from these GE foods than from their non GE counterparts. Some GE foods might even be safer than non GE foods. Corn damaged by insects often contains high levels of humanacins, toxins that grow in the wounds of the damaged corn. Laptests have linked humanacins with cancer in animals. Studies show that most corn modified for insect resistance has lower levels of few monocins than conventional corn damaged by insects. However, biotech foods have had problems in the past. One such problem occurred in the mid 1990s when soybeans were modified using genes from a nut. The modified soybeans contained a protein that causes reactions in humans who are allergic to nuts. While this protein was discovered before any damage was done, critics fear that other harmful proteins created through genetic modification may slip by unnoticed. Moving genes across dramatically different species, such as rats and lettuce, also makes critics nervous. They fear something could go wrong, either in the function of the inserted gene or in the function of the host DNA with the possibility of unexpected health effects. Can biotech foods harm the environment? Most scientists agree that the main safety issues of GE crops involve not people but the environment. Allison snow a plant ecologist at Ohio State University worries that GE crops are being developed too quickly and released before they have been adequately tested. On the other hand, advocates of GE crops argue that some genetically modified plants may actually be good for the land by offering an environmentally friendly alternative to pesticides, which can pollute water and harm animals. Far fewer pesticides need to be applied to cotton plants that have been genetically modified to produce their own natural pesticides.
Paragraph D
While applied chemical pesticides, kill nearly all the insects in a field, biotech crops with natural pesticides only harm insects that actually try to eat those crops. Can biotech foods help feed the world? 800 million people on this planet are mal-nourished, says Chana Patna Prakash, a native of India, and a scientist at Tuskegee University's Center for Plant Biotechnology Research in the USA. And the number continues to grow. Prakash and many other scientists argue that genetic modification can help address the urgent problems of food shortage and hunger by increasing crop quantities. Crops can be engineered to grow in areas with harsh, dry climates or in soils not usually suitable for farming. According to the World Health Organization, an estimated 250 million children in the world suffer from vitamin A deficiency.
Paragraph E
Between 250,000 and 500,000 go blind every year as a result, with half of those children dying within a year of losing their sight. Golden rice, a biotech variety named for its yellow color, is thought by some to be a potential solution to the suffering and illness caused by vitamin A deficiency. Other experts, however, claimed that the biotechnology industry has exaggerated the benefits of golden rice. Golden rice alone won't greatly diminish vitamin A deficiency, says Professor Marion Nestle of New York University. Beta-Carrotine, which is already widely available in fruit and vegetables, isn't converted to vitamin A when people are malnourished. Golden rice does not contain much beta-carrotine and whether it will improve vitamin A levels remains to be seen. What's next? Whether biotech foods will deliver on their promise of eliminating world hunger and improving the lives of all remains to be seen, their potential is enormous, yet they carry risks. If science proceeds with caution, testing new products thoroughly and using sound judgment, the world may avoid the dangers of genetic modification while enjoying its benefits.

课文配套练习 (Reading Exercises)

对应教材 Page 51–57 官方练习：Before You Read、Reading Comprehension 及 Evaluating Arguments 批判性思维图表。

1.
Predicting (p.51) Are biotech foods safe for humans?
2.
Predicting (p.51) Can biotech foods harm the environment?
3.
Predicting (p.51) Can biotech foods help feed the world?
4.
Purpose (p.56) What is the author's purpose in writing the passage?
5.
Detail (Para C, p.56) Which of the following is NOT practiced by conventional breeders?
6.
Inference (Para D, p.56) What is the danger of fumonisins?
7.
Detail (p.56) Which of these concerns about GE crops is NOT mentioned?
8.
Main Idea (Para E, p.56) What is the main idea of the final paragraph?
9.
Matching Effects (p.56) What effect does genetic alteration have on CORN?
10.
Matching Effects (p.56) What concern or effect is associated with modified SOYBEAN?
11.
Matching Effects (p.56) What effect does genetic alteration have on COTTON?
12.
Evaluating Arguments (p.57) Arguments For · Good history: People have been changing plants genetically for ______ of years with no problems.
13.
Evaluating Arguments (p.57) Arguments For · Safe for humans: Studies indicate GE foods do not pose a ______ to human health than non-GE foods.
14.
Evaluating Arguments (p.57) Arguments For · Environmental benefits: GE crops can produce their own ______ pesticides, so farmers can apply fewer chemical pesticides.
15.
Evaluating Arguments (p.57) Arguments For · Environmental benefits: ...so farmers apply fewer ______ pesticides.
16.
Evaluating Arguments (p.57) Arguments Against · Unexpected consequences: Moving genes across different species brings the possibility of ______.
17.
Evaluating Arguments (p.57) Arguments Against · Environmental risks: GE crops are sometimes released before they have been ______.

Critical Thinking · Evaluating Arguments
Look at the arguments for and against biotech foods. Underline any evidence from the reading passage (e.g. statistics, examples) that supports each argument.
Based on the reading, would you personally eat genetically modified foods? Why or why not?