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
考研
One of the least appreciated but most remarkable developments of the past 60 years is the extraordinary growth of American agric
One of the least appreciated but most remarkable developments of the past 60 years is the extraordinary growth of American agric
admin
2017-04-13
56
问题
One of the least appreciated but most remarkable developments of the past 60 years is the extraordinary growth of American agriculture. Farming now accounts for about one tenth of the gross domestic product yet employs less than 1 percent of all workers. It has accomplished this feat through exceptionally high growth in productivity, which has kept prices of food low and thereby contributed to rising standards of living. Furthermore, the exportable surplus has kept the trade deficit from reaching unsupportable levels. Agriculture not only has one of the highest rates of productivity growth of all industries, but this growth appears to have accelerated during the past two decades.
Over the period 1948 to 2004, total farm production went up by 166 percent. The land used for farming dropped by one quarter over the 56-year period, and investment in heavy farm equipment and other capital expenditures decreased by 12 percent. Several developments drove these changes, beginning with the replacement of the remaining horses by tractors immediately after World War II and with the expanding use of fertilizers and pesticides. Later came the adoption of hybrid seeds, genetic engineering of plants and improved livestock breeding. A key element was the U.S. Department of Agriculture’s(USDA)extension service. Operating through land-grant universities and other organizations, it educated farmers on biotechnology, pest management and conservation.
For many years, critics have claimed that modern agriculture is not sustainable, one of the major assertions being that it encourages erosion, which will eventually wash away most of the topsoil. Lost topsoil, the argument goes, is virtually irreplaceable because it takes up to 300 years for one inch of soil to form.
But a detailed study of two large areas, the Southern Piedmont and the Northern Mississippi Valley Loess Hills, showed that based on 1982 data, soil loss has dropped sharply from the very high rates of the 1930s. The study attributed the decrease in soil erosion to the USDA, which urged farmers after World War II to adopt conservation practices such as strip cropping, whereby alternating rows are planted, and leaving plant residues in the fields year-round to inhibit water runoff.
Despite being a robust contributor to the U.S. economy, modem agriculture is not without a
dark side
. Runoff of fertilizers, antibiotics and hormones degrade the environment and can upset the local ecology. If not grown properly, genetically modified crops could spread their DNA to conventional species.
The sharp decrease of soil erosion in 1982 resulted from
选项
A、the education of the USDA on farming technology.
B、the practices of environmental protection on farming.
C、the prevention of water runoff in the two large areas.
D、the protection of plant residues around the whole year.
答案
B
解析
细节推断题。根据1982定位到第四段,第二句话说了此项研究将这一成绩归功于美国农业部在二战后对土地保护所做的努力(conservation practice),因此B项的protection on farming正确。
转载请注明原文地址:https://kaotiyun.com/show/JIbZ777K
0
考研英语一
相关试题推荐
Imaginewakingupandfindingthevalueofyourassetshasbeenhalved.No,you’renotaninvestorinoneofthosehedgefunds(对
Imaginewakingupandfindingthevalueofyourassetshasbeenhalved.No,you’renotaninvestorinoneofthosehedgefunds(对
[A]Analyzingyourowntaste[B]Beingcautiouswhenexperimenting[C]Findingamodeltofollow[D]Gettingthefinallookabsolute
OfallthechangesthathavetakenplaceinEnglish-languagenewspapersduringthepastquarter-century,perhapsthemostfar-re
OfallthechangesthathavetakenplaceinEnglish-languagenewspapersduringthepastquarter-century,perhapsthemostfar-re
Eventoday,youmightthinkmanyAmericanchildrenareindangerofbecomingseriouslyundernourished.Millionsofparentsnever
HarvardprofessorHarveyMansfieldstirredupcontroversyrecentlybycriticizingtheviolentgradeinflationathisinstitution
Itistheurbandriver’smostagonizingeverydayexperience:thesearchforanemptyparkingplace.Circling,narrowlymissinga
Itistheurbandriver’smostagonizingeverydayexperience:thesearchforanemptyparkingplace.Circling,narrowlymissinga
Itistheurbandriver’smostagonizingeverydayexperience:thesearchforanemptyparkingplace.Circling,narrowlymissinga
随机试题
证明、解释、反驳或推销己方观点的过程体现在()
谈判期限
下列何种细菌的动力试验在25℃培养时为阳性,而在37℃培养时为阴性
实现总供求关系的基本平衡,短期应以()。
监理工程师受业主委托对物资供应进度进行控制时,其工作内容包括()
【2012年烟台市市直】体罚学生,经教育不改的教师,由所在学校、其他教育机构或者教育行政部门给予行政处分或解聘。()
某古代水利工程“旱时引水浸润,雨则杜塞水门,故记日‘水早从人,不知饥馑”’。后来三国时蜀相诸葛亮“征丁十二百人护之”,据此判断,这项水利]二程是()。
物权法定原则的具体内容表现为()
为使进程从阻塞态转换为挂起态,使用的原语是()。
下面描述不属于软件特点的是
最新回复
(
0
)