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
My topic today is "The Car and Air pollution. " In particular, I want firstly to discuss the ways in which the car causes air po
My topic today is "The Car and Air pollution. " In particular, I want firstly to discuss the ways in which the car causes air po
admin
2014-01-13
32
问题
My topic today is "The Car and Air pollution. " In particular, I want firstly to discuss the ways in which the car causes air pollution; and secondly, how we can control or reduce air pollution from the car.
First, then, how does the car cause air pollution? 【T1】
What happens is that the car’s internal combustion engine is a kind of chemical factory on a small scale.
It uses a mixture of petrol and air, and this mixture explodes and burns, to produce the energy which propels the car. 【T2】
But while this is happening, many complicated chemical reactions are taking place.
In particular, part of the petrol-air mixture is not completely burned up, and so the exhaust gasses from the engine contain some very dangerous chemicals, such as carbon monoxide, nitrogen oxides, lead and hydrocarbons.
This is the situation, then, and it’s going to get much worse, unless we do something about it. So, let’s focus our attention now on ways of controlling or reducing the amount of air pollution caused by the car.
First, we can discourage the use of cars. For example, we can put higher taxes on petrol and on cars themselves-especially the larger ones that use a lot of petrol.
【T3】
Second, we can encourage alternative methods of transport both between and within urban areas. For instance, we can make train and bus services cheaper and more convenient. And we can build a mass transit system in large cities, particularly an underground railway system such as those in London, New York, Moscow and Tokyo.
Next, we can use a different and cleaner fuel for the internal combustion engine with other designs.
Fourth, we can replace the present internal combustion engine with other designs. There are several possibilities being researched at present, such as electric, gas turbine, and "steam" engines. However, each of these engine designs has its own disadvantages.
【T4】
Last but not the least, we are trying to control the emissions from the internal combustion engine much more strictly. This, for example, is a catalytic converter, which converts the most dangerous ingredients of the car exhaust into water and harmless gases.
As I’m sure you can see, there are problems with each of these ways; but at least they’re a step in the right direction. Probable the best answer is a synthesis of all five.
【T4】
选项
答案
最后,我们正在设法以一种更为严格的方法来调控内燃机所排放的气体。例如,我们可以安装一个催化转换器,这个装置可以将汽车所排放废气中的大部分有害成分转换为水和无害气体。
解析
转载请注明原文地址:https://kaotiyun.com/show/rQQO777K
0
考博英语
相关试题推荐
Ahundredyearsagoitwasassumedandscientifically"proved"byeconomiststhatthelawsofsocietymakeitnecessarytohave
BuildingonthebaseofevidenceandinterpretationinHansen’s(1994)qualitativestudyofworkingpeople’sdiaries,,seas
Likemanyotheraspectsofthecomputerage,Yahoobeganasanidea,【21】intoahobbyandlatelyhas【22】intoafull-timepassion.
(81)Realestate,inbroaddefinition,islandandeverythingmadepermanentlyapartthereof,andthenatureandextentofone’s
IsittruethattheAmericanintellectualisrejectedandconsideredofnoaccountinhissociety?Iamgoingtosuggestthatit
Therearetwobasicwaystoseegrowth:oneasaproduct,theotherasaprocess.Peoplehavegenerallyviewedpersonalgrowtha
Iwillbrieflydiscussthebenefits_____Ifeelhaveresultedfromtheproject.
1999年,中国开始进入老龄化社会。2004年底,60岁以上的人口达到1.43亿,占全国人口总数的10.97%。至此,中国成为世界上拥有最多老龄人口的国家。有专家说1990年底至2003年是中国的“人口红利”(populationbonus)期,出生率下
城市一直在破坏它们的周围环境,并常常为之付出代价。科学家发现,一座老城在泥土下掩埋了千百年就是因为砍树过多而被洪水淹没的。此外,城市会给市民带来许多问题。据估计,到2050年时,城镇居民的数量将在人类历史上第一次超过农村人口数量。随后30年内,下几代人的生
FinallythedirtroadinMainewasleadinghome.Thetiretouchedthefirstprofanityofpavement,andsubtlymyvacationbegan
随机试题
腹部手术后开始给予流质饮食的依据是
患者李某,阑尾炎术后第三天,被安置于普通病房,病房的温度和相对湿度应保持在
患者,男,40岁。劳累后突然呕大量咖啡色胃内容物2小时,既往有乙型肝炎病史。体格检查:心率110次/分,血压110/70mmHg,面色苍白,巩膜轻度黄染,四肢湿冷,腹部平坦,无固定性压痛。患者呕血原因最可能的是
下列属于原络配穴的是
A.哌替啶B.罗格列酮片C.山莨菪碱片D.替硝唑片E.复方利血平—氨苯蝶啶片驾驶员服用后可引起定向力障碍从而影响驾驶的药物是
下列哪项是甲亢病人术前必不可少的药物准备:
矿山建设项目和用于生产,储存危险物品的建设项目,应当分别按照国家有关规定进行( )。
下列情况中,当游客提出换房,导游应立即满足其要求的是()。
哈尔滨圣·索菲亚教堂属于俄岁斯拜占庭式建筑,是哈尔滨现存最大的东正教堂。()
你去办公室给领导送文件。看见领导桌上放了一封关于你的检举信,这时你怎么办?若过了一段时间领导还没有找你谈话,你认为是什么原因?你会怎么做?
最新回复
(
0
)