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
The speaker mainly discusses ______.
The speaker mainly discusses ______.
admin
2009-02-10
64
问题
The speaker mainly discusses ______.
In the early 1800s, the paper industry was still using rags as its basic source of fiber as it had for many centuries. However, the rag supply couldn’t keep up with the growing demand for paper. The United States alone was using 250 thou sand tons of rags each year. And a quarter of that had to be imported. It was clear that a new source of fiber was needed to keep up with the demand for paper. The answer to this problem turned out to be paper made from wood pulp, something that was abundantly available in North America. In Canada, the first wood pulp mill was set up in 1866, and it was immediately successful. But while wood pulp solved the problem of quantity, it created a problem of quality. Wood contains a substance called lignin. The simplest way to make large quantities of cheap paper involves leaving the lignin in the wood pulp. But lignin is acidic and its presence in paper has shorted the life expectancy of paper from several centuries for rag paper to less than a century for paper made from wood pulp. This means that books printed less than a hundred years ago are already turning yellow and beginning to disintegrate, even though books printed much earlier may be in fine condition. This is bad enough for the older books on your bookshelf, and it poses a huge problem for libraries and the collections of government documents, too.
选项
A、books are in poor condition
B、having too many books from the early 1800s
C、not having enough space to store government documents
D、having to import most of the paper they use
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/XR6K777K
0
专业英语四级
相关试题推荐
Inthepast,degreeswereveryunusualinmyfamily.Today,fiveofmybrothersandsistershavedegrees,andtwoarestudying
TheroleofeyecontactinaconversationalexchangebetweentwoAmericansiswelldefined;speakersmakeacontactwiththeey
Somelocaleducationcommissionsrecentlyannouncedteacherswhohaveacceptedgiftsorcashfromstudentsortheirparentswill
Gettingemployedisnolongeraneasytaskforundergraduatestudents.Thatiswhysomehavetakentheinitiativetoworkforfr
(1)Thereareobviousdifferences,ofcourse.LadyGaga’sraw-meatdresswouldprobablynothaveappealedtoMotherTeresaofCal
Smokingbansinpublicplacesarebecomingmoreandmorecommoninmanycountries.Whethertherightsofthenon-smokerstobrea
ThingstobeTaughtinEverySchoolI.Introduction:Importanceofstudents’abilitytodealwiththerealworld.A.Speaker
PassageOne(1)WhentheViaductdeMillauopenedinthesouthofFrancein2004,thistallestbridgeintheworldwonworl
TherealvictoryfortheparticipantsofMarathonraceis______.
AlejandroToledo,aformershoe-shineboyturnedeconomist,isnowPeru’sPresident-elect,followinghisvictorySundayinarun
随机试题
骨肉瘤的好发年龄为:()
背景某宾馆大堂改造装修工程,考虑到施工范围和施工内容较为明确,工期较短,业主与承包商根据《建设工程施工合同(示范文本)》GF一2017—0201签订了固定总价合同。消防系统工程改造内容工程量目前无法确定,合同中约定此部分暂估价为120万元,同时合同约定消
最有助于肺脓肿诊断的症状是
患者,女,症见精神恍惚,心神不宁,悲忧善哭,时时欠伸,舌质淡,苔薄白,脉弦细,属郁证中的哪一证候
肝脏的首过作用是指
该Ig血清中含量水平该Ig之所以对防止新生儿感染有重要意义是因为
国际多式联运经营人可以是:
平等协商的形式包括()。
聪明:愚蠢
A:Howaboutseeingamoviewithmetoday,Alan?B:______
最新回复
(
0
)