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
专升本
In an age when waste today means a lack tomorrow, making use of every available resource becomes more and more important. As coa
In an age when waste today means a lack tomorrow, making use of every available resource becomes more and more important. As coa
admin
2011-05-26
25
问题
In an age when waste today means a lack tomorrow, making use of every available resource becomes more and more important. As coal is being used in greater and greater amounts to produce electricity, larger amounts of ash, by-product of coal, are produced. When coal is burned in a boiler, two kinds of ash by-product are produced, a heavy bottom ash and a fine-as-powder fly ash that is filtered and captured by precipitators. About 10 to 15 percent of the coal by-product is bottom ash which is used like sand on icy city streets and highways and also on highways as paving material. It is the fly ash, however, that is receiving the greater amount of attention. Fly ash may be used as an additive to concrete in the construction of dams, bricks, and roads, and can replace up to 20 percent of the cement used in concrete. As a by-product of burned coal, fly ash requires no additional expenditure of energy to be produced, while cement production requires great amounts of energy.
In addition to using fly ash as a concrete additive, the technology is available to extract the main mineral components-aluminum, silicon, and magnetic. Today, extracting these components is a very expensive process, but the time may come when it is cheaper to extract these products from ash than to mine new supplies.
What can be used as a material to pave roads?
选项
A、The coal by-product.
B、Additive.
C、Fine-as-powder fly ash.
D、Both B and C
答案
A
解析
根据题干找到第一段第三、四句,About 10 to 15 percent of the coal by-product is bottom ash which is used like sand on icy city streets and highways and also on highways as paving material符合题意。
转载请注明原文地址:https://kaotiyun.com/show/TKqC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
(Shoulditraintomorrow)wewouldcancelthegathering.
"Doyouthink______Ishouldattendthelecture?"sheaskedme.
"Vegetableoilisgettingsoexpensive.""Yes,Youget______foryourmoneynow."
Abeamoflightwillnotbendroundthecornersunless______todosowiththehelpofareflectingdevice.
Itisreportedthattrafficaccidentsarehappeninginthatcitywithincreasing______(frequent).
Forthispart,youareallowed30minutestowriteacompositiononthetopic:GettingtoknowtheWorldOutsidetheCampus.You
Everywomandreamsofreceivingahugepricelessdiamond.Nowspacescientists【C1】______thattheyhavediscoveredthelargestdi
______makesmendifferentfromtheotheranimalsisthattheycanthinkandspeak.
Whenyouarebeinginterviewedforajob,rememberthatit’s【61】formanypeopletobenervous,【62】insuchastress-producingsit
随机试题
控制支气管哮喘症状的首选药是
不符合慢性肾盂肾炎的描述是
乳池闭锁治疗错误的是
偏于健脾者偏于安神者
区别大黄酚与大黄素的方法有
孙某有一辆汽车,估价20万元,6月1日孙某向李某借款10万元,订立汽车抵押合同并于当天办理抵押登记。6月2日,孙某向赵某借款10万元,又以该汽车抵押登记。后孙某不能还款,变卖汽车得款16万元。则李某、赵某的抵押权( )。
某地方政府准备修建乡村公路网,其宏观目标定位为:改善当地基础设施条件,帮助农民摆脱贫困。该项目的可行性研究报告提出的项目目标层次包括下列因素:(1)改善农副产品运输条件,沟通与外界的联系渠道。(2)推动当地农副产品加工业的发展。(3)上级政府财政拨款
斜坡堤的砂垫层顶面高程(),砂垫层厚度不小于设计厚度。
下列关于复式记账法的说法,错误的是()。
①各地考试选拔②回来报效祖国③外语人才奇缺④送往国外留学⑤政治文化强化培训
最新回复
(
0
)