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
(1)More and more of the world’s supply of seafood is coining from farms. (2)Although 80% of the world’s seafood comes from m
(1)More and more of the world’s supply of seafood is coining from farms. (2)Although 80% of the world’s seafood comes from m
admin
2021-08-31
61
问题
(1)More and more of the world’s supply of seafood is coining from farms.
(2)Although 80% of the world’s seafood comes from marine harvests, there is a major shift under way toward aquaculture now.
(3)Nearly 40% of salmon marketed today are raised in captivity, compared with 6% a decade ago. Forty percent of all clams, oysters, and mussels are produced in farm environments, along with 65% of freshwater fish. Between 1990 and 1996, fish-farming production rose from 12.4 million to 23 million tons worldwide, writes Anne Piatt McGinn in an article for World Watch magazine.
(4) "The fact that world seafood supplies continue to increase at all is due almost entirely to the phenomenal growth in aquaculture," says McGinn, a research associate at the World Watch Institute. Commercial aquaculture is driven by rising human population at a time when over harvested wild fish stocks are in decline and conventional farm production has leveled off.
(5)Biotechnology is contributing to high-yield aquaculture through transgenics—the transfer of genes from one species to another. Researchers introduce desirable genetic traits into fish, creating hardier stocks. For example, some species of fish have a protein that allows them to live in Arctic waters. By transplanting this "anti-freeze" gene into other species, researchers have created more fish that can survive in extremely cold water, according to Ag-West Biotech, Inc., in Saskatchewan, Canada.
(6)Biotechnologists are attempting to improve a wide range of genetic traits in fish used for aquaculture, developing fish that are larger and faster-growing, more efficient in converting feed into muscle, more tolerant of low oxygen levels in water, and better able to resist disease.
(7)Researchers also are seeking plant-based sources of food as a more efficient alternative to fishmeal. The use of plant protein on fish farms could take some of the pressure off wild fish stocks and address the problem of phosphorous pollution because plants do not contain high phosphorus levels. Wheat, canola, and canola oil are being used as alternative feed for aquaculture, according to Ag-West Biotech, Inc.
(8)While aquaculture produces a reliable source of protein, the industry is rife with environmental problems, asserts McGinn. Perhaps the biggest concern is water pollution: Fish waste and uneaten food accumulates at farm sites and can float directly downstream into water supplies. Farm-related nutrient wastes as well as nitrogen and phosphorus also promote the spread of algal "blooms" that deplete oxygen and kill marine life.
(9)Aquaculture is also an inefficient user of resources, McGinn charges. Fish farms need protein feed, and about 17% of ocean fish, an over harvested wild resource, becomes food for captive-bred fish. "An estimated five kilograms of oceanic fish reduced into fishmeal are required to raise one kilogram of farmed ocean fish or shrimp, representing a large net protein loss," says McGinn.
(10)Fish farming does not have to be an inefficient or polluting industry. McGinn predicts that many consumers will choose sustainably produced fish in the future, just as they prefer dolphin-free tuna today.
All the following statements are the reasons why commercial aquaculture is pushed forward EXCEPT ________.
选项
A、the human population is increasing fast
B、the wild fish stocks are decreasing due to over fishing
C、the cost of developing aquaculture is comparatively low
D、there is no improvement in conventional farm production
答案
C
解析
细节题。第4段末句提到了三个刺激水产养殖业快速发展的原因,只有C项不是原因之一。注意题干中的EXCEPT。根据提干中的关键词commercial aquaculture定位于第4段末句,便可确定正确答案为选项C。其他三个选项文中该句均有提到。
转载请注明原文地址:https://kaotiyun.com/show/2BtK777K
0
专业英语四级
相关试题推荐
A、Movesomesummersportstothewintersports.B、IntroducesomenewsportstotheOlympics.C、Reducesomeindoorsummersports.
AmericanFamiliesTypesofAmericanfamilies-thetraditionalAmericanfamily:aworkingfather,【T1】______,andtwoor
Theitalicizedpartinthesentence"Manypeopleobservedtheshipleavingtheharbor."isan______.
UnionsNearly100yearsago,America’sworkingpeoplebegantojointogether/toimprovetheirwagesandtheirworkingsitu
Itisoftenseenthatsomepeoplechoosetoleavebigcitiesandliveinthecountryside,whileotherslaythemselvesouttosee
U.S.News______rankingsofcollegessince1983.Theyareaverypopularresourceforstudentslookingtoapplytoauniversityc
Mybrotherlikeseatingverymuch,butheisn’tvery______aboutthefoodheeats.
They’vedecidedtopostpone_____havingafamilyforawhile.
CounselingTeamandtheServices1.Counselingteam.NaomiFlynna.Targeting:Thosewhohaveneverusedacounselorbe
(1)BrothersAaron,FinnandRyanFreeman-HaydensetoffforSt.Colman’sSchoolinBallindagginfullofexcitementandnerves
随机试题
资产负债表项目的质量分析不包括()。
下列禁止进入中药材专业市场的中药材是
在委托诉讼中,需要委托人特别授权的事项有( )。
下列有关同一控制下企业合并形成的长期股权投资初始投资成本的表述中,正确的是()。
我国三大平原不包括()。
构成法律的基本单位是()
论软件可靠性评价软件可靠性评价是指选用和建立合适的可靠性数学模型,运用统计技术和其他手段,对软件可靠性测试和系统运行期间的软件失效数据(也可能包含软件生命周期内其他可靠性数据)进行处理,并评估和预测软件可靠性的过程。软件可靠性评价是软件可靠性
AcademicMobilityScholarsandstudentshavealwaysbeengreattravelers."Academicmobility"isnowoftenstatedasafunda
The______crownjewelsarekeptintheTowerofLondon.
Singaporeisoneoftheworld’ssmallestcountriesbutitisalsooneofthemostsuccessfulcountries.Itseconomicgrowthhas
最新回复
(
0
)