首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
While it can’t yet be said that every mouthful of food has been changed through genetic engineering, it is likely that almost ev
While it can’t yet be said that every mouthful of food has been changed through genetic engineering, it is likely that almost ev
admin
2010-05-09
76
问题
While it can’t yet be said that every mouthful of food has been changed through genetic engineering, it is likely that almost every American has had a mouthful of engineered food.
Take the soybean, for example. About 55 percent of last year’s crop was genetically engineered in some fashion, reports the American Soybean Association. And though few Americans sit down to a plate of soybeans for dinner, these soybeans arrive through the back door as an additive to scores of foods like cooking oils, salad dressings, coffee creamers, beer, cereals and candy.
America is on the verge of a second green revolution. The first tripled world food output over the course of a mere three decades during the late 20th century. Scientists boosted crop yields by crossbreeding (杂交) related plants that add desirable traits. Then farmers added fertilizer, pesticide, and irrigation in order to make the high-yield crops thrive.
Now that those gains are leveling off, scientists are looking to biotechnology to increase food production even more. This time, instead of breeding plants with their closest relatives, scientists are inserting genes. For example, genes from flounders can help ordinary plants like tomatoes and strawberries fight the cold. Researchers are also inserting bacterial genes into corn and soybean plants to better protect them from insects or render them immune to certain herbicides (除草剂).
The technology has enormous potential. The application of biotechnology is going to produce a set of possibilities that we simply cannot conceive of, even in our most imaginative flights of fancy. For farmers, crops engineered with genes that resist cold, drought, or other adverse weather conditions can boost crop yields with less money and effort. For consumers, that could mean cheaper food. Such crops would also help feed and better nourish people in developing nations, such as drought-ridden Africa.
But as these crops begin infiltrating (渗透) our food supply, environmental and consumer groups have begun to question whether potential risks to the environment and human health have been adequately studied. Last year, for example, biologists for the first time found evidence suggesting that planting genetically modified com in open fields may kill butterflies who feed on the corn’s pollen. Scientists are also questioning whether foods with a gene inserted to improve one area of their performance could prove detrimental in another: For one thing, the genes might cause allergic reactions in people who never had a reaction to that food before.
What’s the biggest difference between the first and second green revolution in America?
选项
A、The first green revolution is to improve the food output while the second is not.
B、The second green revolution is based on the theory of inserting genes while the first depends on that of crossbreeding.
C、The technology that is used in the second green revolution has much more enormous potential than that of the first’s.
D、The second green revolution has caused harm to the environment while the first has not.
答案
B
解析
细节推理题。第一次和第二次农业革命的差别最主要的就是技术上的差别,这从文章的第四段可以看出——一个是杂交技术,另一个是基因工程,所以答案是B。
转载请注明原文地址:https://kaotiyun.com/show/n7OK777K
0
大学英语六级
相关试题推荐
A、Tosearchforthemissingpeople.B、Toinvestigateafireononeoftheislands.C、Tolookforthemissingwoman.D、Torescue
A、Thetwospeakerswillcontinuetalkingandbecomefriends.B、Thetwospeakerswillspendtheirvacationtogether.C、Thewoman
Whatcowsconstituteshighpercentageinthetotalcowsbutcheredeachyear?WhywillAmericanswanttoexportbeeffromanimal
"Whatadifferenceawordmakes?"Theissueofsemantics(语义学)hasbeenanongoingcomplaintagainstthemedia,whichhasbeenc
A、Acceptthejobofferfromthebookstore.B、Acceptthejobofferfrom1BM.C、IntheholidayworkinIBMandinthenextschool
Mylittledaughter,Mary,__________________________(进入大学三个月了才开始慢慢适应校园生活).
A、Hehastochangethetopicforhiscomposition.B、HehasfallenbehindothersinEnglishclass.C、Hehasn’tmadeuphisminda
A、Thenextday.B、OnSaturday.C、Inthreedays.D、Inoneweek.BWhenishersister’sbirthday?信息明示题。女士询问包裹能否在自己妹妹过生日那天.电就是周六寄到,
A、Followpolicemen’sdirections.B、Keepaneyeontheweather.C、Avoidsnow-coveredroads.D、Drivewithspecialcare.D细节题。本题询问监
A、Atthepostoffice.B、Athishomeaddress.C、Athismountaincabin.D、Athisuncle’saddress.D
随机试题
当事人逾期不履行行政处罚决定的,作出行政处罚决定的行政机关可以申请()强制执行。
A、Helpingstudentsfindthebooksandjournalstheyneed.B、Supervisingstudyspacestoensureaquietatmosphere.C、Helpingstu
原发性颗粒性固缩肾见于()
众所周知,生物多样性是地球生命体系稳态延续的基本前提。但人类社会的活动由于受到价值定位的影响,总会对某些生物物种过分偏爱,而对另一些生物物种漠然视之,甚至对某些物种厌恶有加,因而在地球生命体系中并存的生物物种,在人类社会中总会受到各不相同的待遇。这种不公正
下列属于复合式组织结构优点的是()。
某单位发生车辆伤害事故,导致某员工受伤,经过鉴定,该员工为三级伤残,根据《工伤保险条例》的规定,下列关于对该员工一次性伤残补助的金额是()。
下列表述,错误的一项是()。
如果用一个圆来表示词语所指称的对象的集合,那么以下哪项中三个词语之间的关系符合下图()。
某软件公司欲开发一个图像处理系统,在项目初期,开发人员对算法的效率、操作系统的兼容性和人机交互的形式等情况并不确定。在这种情况下,采用(23)方法比较合适。
Whatproportionofcell-phoneusersusetheirphonesregularlywhiledriving?Whenaredriversatgreatestriskfromdrowsines
最新回复
(
0
)