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
2014-03-21
63
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、turned out high-quality paper
B、used wood imported from the United States
C、caused a serious environmental problem
D、was a ready market for its product
答案
A
解析
转载请注明原文地址:https://www.kaotiyun.com/show/EtUK777K
0
专业英语四级
相关试题推荐
Decidewhichofthechoicesgivenbelowwouldbestcompletethepassageifinsertedinthecorrespondingblanks.Markthebestc
【C1】______arethemissionsofalearnedsocietyinaneraofdigitalnetworks?【C2】______theAmericanCouncilofLearnedSociet
Drunkendrivinghasbecomeanational【C1】______.EveryhourofeverydayaboutthreeAmericansonaveragearekilledbydrunke
Drunkendrivinghasbecomeanational【C1】______.EveryhourofeverydayaboutthreeAmericansonaveragearekilledbydrunke
HowmuchfundswouldbereleasedfromMacaubankintheefforttosettlenuclearprobleminNorthKorea?
Rosamondfeltunhappywithoutany______ofhisprojectatthemeeting,
Thepopularityofthefilmshowsthatthereviewers’fearswerecompletely
Becauseoftheeconomiccrisis,industrialoutputintheregionremained
Atthreethousandfeet,wideplainsbegintoappear,andthereisneveramomentwhensomedistantmountainisnot______.
"OntheInternet,nobodyknowsyou’readog,"readthetitleofafamousPeterSteinercartoon,(1)_____nowhereisittruertha
随机试题
大型机床的基础使用多年后会变得疏松,应对其进行整修。( )
异位ACTH综合征患者,下列哪项是最可能出现的生化特征
心房扑动合并冠心病患者禁忌使用
下呼吸道不包括
以下各项中,不是木质包装材料优点的是()
中国第一个资产阶级革命政党是()。
出人头地:苏轼
被告人刘某在某住宅区行窃时,被邻居张某撞见。张某见状大声呼喊:“抓贼!”被告人刘某用木棒将张某击倒在地,携赃物逃跑。请问:对刘某应如何定罪?理由是什么?
某工厂更新设备,2019年初贷款100万元,从该年年末开始,按照复利计算原则,本利打包,每年年末偿还固定金额,10年还清,年利率3%,则每年需要偿还的金额是()万.(精确到两位小数1.0310≈1.34)
Mysisterisquite______andplanstogetanM.A.degreewithinoneyear.
最新回复
(
0
)