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
Planes may account for only 2 per cent of the world’s carbon emissions, but it is a figure destined to rise. The aviation indust
Planes may account for only 2 per cent of the world’s carbon emissions, but it is a figure destined to rise. The aviation indust
admin
2015-04-10
38
问题
Planes may account for only 2 per cent of the world’s carbon emissions, but it is a figure destined to rise. The aviation industry is expanding at a dramatic rate, around 5% a year. Twice as many passengers are likely to be passing through British airports in 2020 compared with today, and three times by 2030.
As the developed world acknowledges climate change warnings, the carbon emissions from other industries will fall. The aviation industry’s output will therefore account for an even larger percentage of emissions. One calculation, by the Climate Change Research(CCR), suggests the U. K. aviation industry could end up accounting for every gram of our carbon quota by 2040. Such calculations suppose aircraft designers cannot clean up their act, a suggestion firmly rejected by experts who point to a massive research program aimed at cutting fuel use by planes by around 50% by 2020, a move that would also halve their carbon emissions.
To reach that aim, a key factor will be lightweight composites, materials made of several components, including carbon fibers. These are as strong and flexible as metal but as light as plastic. Planes such as the Airbus A340 are already made of material that is 10 per cent carbon composite. This cuts weight, decreases fuel use and reduces carbon emissions. The next generation of aircrafts, will make even more use of composites: a tremendous saving in weight, fuel and carbon.
Then there is the simple matter of air traffic control. At present, individual countries have their own routes for aircraft crossing their airspaces. "Essentially aircraft travel on doglegs across Europe, and that is very inefficient in terms of fuel use," said Dr. John Green, of the Royal Aeronautical Society. "We need to rationalize air traffic control so that planes fly in straight, energy-efficient lines, an idea that is now being discussed in the EU. "
Finally, there is aviation fuel. Making it ecologically friendly poses the greatest challenges of all. Biofuels can be used as petrol and diesel substitutes for cars and lorries, but not in planes. "Biofuel is essentially alcohol, and that burns at the wrong temperature for aircraft engines," says Green. "We can use coal to make kerosene, which we could burn in aircraft engines, but that does not help the issue of global warming, of course. " But this does not stop scientists from dreaming. One idea, put forward by the U. S. geneticist Craig Venter last week, would be to create micro-organisms, fitted with artificial chromosomes, which could convert sunlight into fuels that could be burnt in aircraft. These would not involve burning fossil carbon and would be the perfect green fuel. It is still a far-off prospect but realistic, say biologists.
According to the text, what can we learn about aviation fuels?
选项
A、Biofuels can be used as replacement for vehicles as well as planes.
B、Neither biofuels nor coals can be used for planes.
C、The idea of green fuel is to change solar energy into fuels.
D、The idea of green-fuel, which is only an illusion, is challenged and doubted by scientists.
答案
C
解析
根据本文,关于航空燃料我们可知:[A]生物燃料可作为汽车和飞机的燃料的替代品。[B]生物燃料和煤都不适用于飞机。[C]绿色燃料就是将太阳能转化成燃料。[D]绿色燃料只是一种幻想,受到了科学家们的挑战和质疑。根据题干关键词aviation fuels可以定位到第五段。[C]为第五段倒数第二句的同义转述,故为正确答案。根据该段第三句可知[A]不符合事实,biofuels的燃烧温度不适用于飞机引擎。从第五句可知飞机可以使用coal作为燃料,但是对于环保没有帮助,所以[B]也不符合文意。[D]中的illusion意为“幻想;错误的观念”,显然与最后一句话不符,所以可以排除。
转载请注明原文地址:https://kaotiyun.com/show/jW74777K
0
考研英语一
相关试题推荐
(46)Womenmakeup40percentoftheworld’sworkforceinagriculture,aquarterinindustry,andathirdinservices.Womenfar
(46)Womenmakeup40percentoftheworld’sworkforceinagriculture,aquarterinindustry,andathirdinservices.Womenfar
Intheearly1800s,groupsofEnglishworkerswreckedmachinesthattheyfeltthreatenedtheirjobs.(46)Theywerecalled"Ludd
It’snevertooearlyortoolateforaparenttobecomeateacher.Inthisageofteacheraccountability,endlessschooltesting
It’snevertooearlyortoolateforaparenttobecomeateacher.Inthisageofteacheraccountability,endlessschooltesting
It’snevertooearlyortoolateforaparenttobecomeateacher.Inthisageofteacheraccountability,endlessschooltesting
WhyisEnglishsodifficult?ItisoftenthoughtthatthenumberofwordsintheEnglishlanguageisamajorreason,butthisis
Carbondioxideisa"greenhouse"gas,whichmeansthatithelpstotrapheatintheatmosphere,(46)Morecarbondioxideonthef
Deathisadifficultsubjectforanyone,butAmericanswanttotalkaboutitlessthanmost.Theyhaveaculturalexpectationth
随机试题
含较大量嘌呤食物(75~150mg/100g食部)有:_______和鹅、鸽、野鸭、鹌鹑、鲤鱼、比目鱼、豆制品、干豌豆、鸡汤、肉汤、河鳗、黄鳝、贝壳类水产等。
在电位滴定过程中,下列仪器和试剂不必要的是()。
A.血管内皮损害,血管壁有炎症、坏死和血栓形成B.皮肤及内脏血管损害更严重,有广泛血管腔内血栓C.病变以脑组织为主,有明显的充血和水肿,颅内压升高,可形成脑疝D.病变主要在大脑半球表面和颅底E.以上都不是流脑败血症期病理变化是
男性,36岁。12小时前工作中突然出现右上腹痛,继之出现豆油色尿,半小时前出现上腹痛向腰背部放散,俯首弯腰查减轻腹痛,血压120/180mmHg,呼吸18次/分。下列检查哪项可能出现异常且最有意义()
A.纳洛酮B.布托啡诺C.右丙氧芬D.苯噻啶E.可待因结构中含有环丁烷甲基,属部分激动剂的药物是
[问题一]该工程每月拟完工程计划投资是多少(每月按30天计算)?[问题三]试计算第4月末、第8个月末的投资偏差与进度偏差,并分析原因?
下列项目应计征营业税的是()。
具有决策性和制约性的公文是()
【2015.辽宁鞍山】在知觉过程中,人们力求根据已有知识经验对知觉对象作出某种解释,使其具有一定意义,即知道它“是什么”,并能用语词把它表示出来,这叫作()。
Foreignaidisanimportantpartofinternationaleffortstoreducepoverty.TheUnitedStatesAgencyforInternationalDevelopm
最新回复
(
0
)