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
As the cost of gas and oil for home heating has gone up, many Americans have switched from these fuels to wood for heating their
As the cost of gas and oil for home heating has gone up, many Americans have switched from these fuels to wood for heating their
admin
2012-10-20
64
问题
As the cost of gas and oil for home heating has gone up, many Americans have switched from these fuels to wood for heating their homes. In 1973, approximately 200,000 wood-burning stoves, intended for home use, were sold in the United States; by 1979, this figure had reached one million; and by the end of 1981, there were as many as seven million home owned wood-burning units in operation in the U. S.
In addition to low fuel bills, many people choose these stoves because their initial cost is very low (the prices range from $ 50 kits to $ 5,000 top-of-the-line models), and because new technology has made wood fires more efficient, cleaner, and, therefore, safer than ever before.
One new technological feature of this type is the catalytic(催化) combustor which adds about $ 100 to $ 200 to the cost of the stove, but which causes much more complete combustion (燃烧) of the wood and therefore bums up more of the pollutants left by incomplete combustion and produces more heat.
A second cost-saving innovation is a device which agitates the wood, increasing the amount of oxygen that reaches the center of the wood pile, and leading to more efficient combustion. The real advantage of this device is that it allows the owner to make use of cheap sources of wood such as dirty wood chips (an industrial by-product) that have almost no commercial value, cost as little as $ 20 a ton, and burn very inefficiently in furnaces without an agitator.
According to the passage, the number of wood-burning stove sold for home use ______.
选项
A、went up fivefold over a six-year period
B、rose to seven million during the seventies
C、multiplied thirty-five times between 1973 and the beginning of 1981
D、increased by 6,000,000 over an eight-year period
答案
A
解析
文中第一段说1973年有20万燃木家用取暖炉出售了;到1979年,此数字达到一百万;到1981年末,此数字达到了七百万。因此对照后,A项正确。
转载请注明原文地址:https://kaotiyun.com/show/XLhK777K
0
专业英语四级
相关试题推荐
Whydoadultsbelievethatalcoholicawarenessprogramsteachyoungpeoplenottoover-drink?Recently,readinganarticleabout
Atthefall2001SocialScienceHistoryAssociationconventioninChicago,theCrimeandJusticenetworksponsoredaforumonth
WhichoneofthefollowingisNOTtrueaccordingtotheaccident?
ItispossibleforstudentstoobtainadvanceddegreeinEnglishwhileknowinglittleornothingabouttraditionalscholarlymet
OurvisittotheexcavationofaRomanfortonahillnearCoventrywasofmorethanarchaeologicalinterest.Theyear’sdighad
Ms.Smithwas______pleasedwhenheardherdaughterfailedtheEntranceExamtoCollegeagain.
ScientistshadthoughtpeoplebeganmanipulatingfiretocreatetoolsinEuropeabout25,000yearsago.Butthenewfindssugge
Please______fromsmokinguntiltheairplaneisairborne.
Thelinebackerandcaptainoftheteam______mostvaluableplayer.
______youhaveseenbothfighters,______willwin
随机试题
Womenemployeesworkharderandlongerthanmendo,accordingtoanewstudybyindependentresearchconsultancythePonemonIns
求56的水平、垂直渐近线.
患儿,女,5岁。诊断为嵴下型室间隔缺损,左向右分流,可了解其峰值跨瓣压差的参数为
患者,男性,60岁。颞部2cm×2cm大小黑素斑块,略隆起于皮面,边界清楚但不规整,黑色不均匀,近2个月来缓慢增大。该患者诊断应首先考虑
职业健康安全与环境管理体系作业文件包括()。
A公司当年的公司净利润为6000万元,发行在外的总股数为3000万股,净资产为8000万元,则A公司的每股收益为()元,股本收益率为()。
长期借款筹资与长期债券筹资相比,其特点是()。
(2017年)2016年4月4日,甲公司从乙银行借款80万元,用于购置A型号自行车1000辆,借款期限自2016年4月4日至2016年6月4日,并以价值90万元的自有房屋一套为乙银行设定抵押,同时,乙银行与丙公司签订书面保证合同,约定丙公司为甲公司的借款
某小学在课余时间组织学生参加航模小组、英语小组、小乐团等,以丰富学生的课余生活。其中足球小组的课外活动属于()。
许多数据表明,即使被公认为环境质量优良的城市公园,也存在着不容忽视的土壤污染,而在广袤的农村,土壤污染的影响更是早已有所显露。在我国湖南、广西、贵州的某些地区,土壤重金属污染已相当严重,并导致较大范围的健康问题。但到目前为止,科学家对我国农村和城市土壤污染
最新回复
(
0
)