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
You might think a little global warming is good for farming. Longer, warmer growing seasons and more carbon dioxide(CO2)—what pl
You might think a little global warming is good for farming. Longer, warmer growing seasons and more carbon dioxide(CO2)—what pl
admin
2013-07-11
53
问题
You might think a little global warming is good for farming. Longer, warmer growing seasons and more carbon dioxide(CO
2
)—what plant wouldn’t love that? The agricultural industry basically agrees on that. But global warming’s effects on agriculture would actually be quite complicated—and mostly not for the better.
It’s true that some crops will prosper on a warmer planet, but the key word there is "some." According to a government report, higher CO
2
levels and longer growing seasons will increase yields for fruit growers in the Great Lakes region. But many major American crops already use CO
2
so efficiently that more of it probably won’t make much difference to them.
What will make a difference are all the other things we’ll have more of as temperatures rise—namely droughts(干旱), bugs and big storms. More droughts mean lower crop yields. Melting snow in the Western U.S. will increase water availability in spring but decrease it in summer, forcing farmers to change cropping practices. As insects that eat crops adapt their migration patterns to our warmer climate, farmers will have to either use more insecticide or plant hardier crops.
Farmers on both coasts are already starting to reap some of what the nation’s fossil-fuel addiction has sown. Crops in those regions require a certain number of colder days, or "winter chill" before they break dormancy(冬眠)and begin flowering. Too few cold days breaks the plants’ flowering schedule which in turn affects pollination(授粉)and hurts yield.
So, given how much is at stake for them, how are farm states working to shape climate legislation? In response to agricultural demands, the Waxman-Markey bill frees the agricultural industry from CO
2
emission limits and gives up control over what activities guarantee carbon offset credit to the Agricultural Department.
Some farmers—and some farm state congressional leaders—have argued that because plants convert CO
2
into oxygen, agricultural lands store more CO
2
than they emit. This is only theoretically true. What we can say with certainty is that, like most big industries, farming is fossil-fuel intensive—large quantities of CO
2
are emitted from farm equipment such as irrigation pumps and tractors.
Under the influence of global warming, the yields of American crops will______.
选项
A、be greatly enhanced
B、be certainly reduced
C、still remain stable
D、be hard to predict
答案
D
解析
该句提到温室效应对农业的影响是相当复杂的,甚至很有可能是以不良影响居多,由文中的quite complicated和mostly可知,文中未对全球变暖对农业的影响是好是坏作出结论,农作物的产量是升是降也就无从预测,故D为本题答案。
转载请注明原文地址:https://kaotiyun.com/show/yW07777K
0
大学英语四级
相关试题推荐
A、partofthebrainisnotusedatall.B、Partofthebrainbecomesmorepassive.C、Ittakeslongertoprocessvisualinformatio
A、Monday,Wednesday,andFriday.B、TuesdayandSaturday.C、SaturdayandSunday.D、TuesdayandThursday.D
A、Parents.B、Children.C、Breadwinners.D、Bankmanagers.B预览选项可知,本题可能考查短文的目标读者是谁。由短文中提到的aren’t…breadwinner,allowance及Forkids推断,短
A、She’sapoorstudent.B、Sheshouldn’tworryabouthergrades.C、Shedoesn’tliketotalkabouthergrades.D、Shehasn’tgothe
A、Theeffectswereverygood.B、Theactingwasjustso-so.C、Theplotwastoocomplicated.D、Thecharacterswerelifelike.A男士表示
Mostpublishingisnow"electronic"inthesensethatbooks,magazines,andnewspapersarepreparedoncomputers,andexistasc
A、Language.B、Culture.C、Misinterpretation.D、Disagreement.C文中一开始就谈到,如果交流的某一方有误会,那么交流中就出现了错误,因此答案是C。
Itwasessentialthattheapplicationforms______(截至期限前送回)
Whentheyadviseyourkidsto"getaneducation"ifyouwanttoraiseyourincome,theytellyouonlyhalfthetruth.Whatthey
A、Lendingsomethingtoastudent.B、Readingastudent’sapplication.C、Askingforsomefinancialaid.D、Borrowingmoneyforabu
随机试题
提出文学创作“性灵说”的晚明作家是( )
在我国,物权的变动一般以物的交付为公示方式,但法律另有规定除外,当事人不得另外约定。()
婴儿从母体获得的抗体开始消失的月龄是
甲公司授权其业务员张某购买一批建材,甲公司向张某签发了授权委托书,但委托书中并未明确授权委托期限。后不久甲公司与张某解除了劳务关系,张某怀恨在心,恶意与乙公司签订合同购买一批建材,给乙公司造成了经济损失,其法律后果应该由()。
甲公司生产的B产品的主要销售市场在美国,因此与B产品有关的资产产生的预计未来现金流量是以美元为基础计算的。2017年12月31日甲公司对主要生产B产品的C设备进行减值测试。C设备系甲公司2014年12月30日购入,该设备的原价为20000万元人民币,预计使
()是联邦德国战后第一部高等教育法,它保留了德国大学民主自治的传统,同时又注重发掘大学的潜力,使之适应社会的新需要。
经济学家:现在中央政府是按照GDP指标来考量地方政府的政绩。要提高地方的GDP,需要资金。在现行体制下,地方政府只有通过转让土地才能筹集大量资金。要想高价拍卖土地,则房价必须高,因此地方政府有很强的推高房价的能力。但中央政府已经出台一系列措施稳定房价,如果
下面的函数调用为:fun(x+y,3,min(n-1,y))则fun的实参个数是()。
考生文件夹下存在一个数据库文件“samp3.accdb”,里面已经设计好表对象“tNorm”和“tStock”、查询对象“qStock”和宏对象“m1”,同时还设计出以“tNorm”和“tStock”为数据源的窗体对象“fStock”和“fNorm”。试在
【B1】【B9】
最新回复
(
0
)