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
DEFORESTATION IN NORTH AMERICA 1 The land area of the United States and Canada is just over 4.8 billion acres. When large numb
DEFORESTATION IN NORTH AMERICA 1 The land area of the United States and Canada is just over 4.8 billion acres. When large numb
admin
2012-01-14
92
问题
DEFORESTATION IN NORTH AMERICA
1 The land area of the United States and Canada is just over 4.8 billion acres. When large numbers of Europeans began to arrive in the eighteenth century, almost one-third of that area was covered with old-growth forests. In the eastern half of the continent, nearly 90 percent of the land was thick with forests of elm, ash, beech, maple, oak, and hickory. By the end of the nineteenth century, after several decades of intensive deforestation, only half of the original forests remained.
2 During the first two centuries of European colonization, settlement was concentrated along the East Coast, having almost no effect on the vast forests covering the continent. Then, in the first half of the nineteenth century, agriculture expanded and settlers began to move westward in search of land for new farms. Land for agriculture came almost exclusively from clearing forests. The demand for farmland and timber continued to soar, and by 1850, more than 100 million acres of old-growth forest had been cut or burned off in the Northeast, the Southeast, the Great Lakes region, and along the St. Lawrence River.
3 Along with agriculture, industrialization was a major cause of deforestation. The Industrial Revolution was fueled by North America’s abundance of wood, as iron makers relied on charcoal, or charred wood, to fire their furnaces. Hardwoods such as oak produced the best charcoal, which charcoal burners made by slowly burning logs in kilns until
they
were reduced to concentrated carbon. It took eight tons of wood to make two tons of charcoal to smelt one ton of iron. Thus, the
toll
on the forests was high, as countless acres were cut to feed the furnaces of the iron industry.
4 The transportation technology of the Industrial Revolution contributed greatly to deforestation. The river steamboats that came into operation after 1830 had a
voracious
appetite for wood. To keep their wheels turning, steamboats typically took on fuel twice a day. The wood was supplied by thousands of"
wood hawks
" along the banks of the Ohio and Mississippi with stacks of cut firewood. Annual consumption of wood on riverboats continued to increase until 1865. Consequently, river valleys that had the heaviest traffic were stripped of their forests.
5 After 1860, immigration and westward expansion surged, and railroads swept over the continent. Clean-burning hardwood was the preferred fuel of the "iron horses," which required the cutting of 215,000 acres of woodland to stay in operation for one year. Not only did wood fuel the steam engines, but enormous amounts of oak and locust also went into the manufacture of railcars, ties, fencing, bridges, and telegraph poles. Railroads in the United States and Canada stretched from coast to coast by 1885, and each additional mile of railroad meant at least two more miles of fencing and 2,500 ties.
6 Other major consumers of forest products included ordinary homeowners.
More than four out of five of the houses constructed in the early nineteenth century-from log cabins to clapboard cottages-were built mainly of wood and roofed with wooden shingles.
All were filled with wooden furniture. Two-thirds of all households in North America were heated by open, wood-burning fireplaces, and it took between 10 and 20 acres of forest to keep a single fireplace burning for one year.
7 Throughout the century, the timber industry continued to supply the single most valuable raw material for a rapidly expanding population. Between 1840 and 1860, the annual production of lumber rose from 1.6 million to 8 billion board feet. This increase was made possible by the widespread application of steam power. Wood-fueled steam engines powered the sawmills, moved and barked the logs, and finished the boards. Railroad lines were now built right into the forests so that felled logs could be shipped directly to market. These innovations had their greatest impact in the Great Lakes region. By 1890 the technology of the timber industry had triumphed over the natural abundance of the forests, and woodlands that had once seemed endless were now depleted.
According to paragraph 7, the tremendous increase in the production of lumber was primarily due to
选项
A、the availability of land
B、an increase in the labor supply
C、innovations in technology
D、timber industry leadership
答案
C
解析
The tremendous increase in the production of lumber was primarily due to innovations in technology. Clues: ...the annual production of lumber rose from 1.6 million to 8 billion board feet. This increase was made possible by the widespread application of steam power Wood-fueled steam engines...; Railroad lines...; These innovations had their greatest impact....(1.1)
转载请注明原文地址:https://kaotiyun.com/show/f3yO777K
0
托福(TOEFL)
相关试题推荐
Completethesummarybelow.ChooseONEWORDONLYfromthepassageforeachanswer.Writeyouranswersinboxes21-26onyourans
Completethesummarybelow.ChooseONEWORDONLYfromthepassageforeachanswer.Writeyouranswersinboxes21-26onyourans
Completethesummarybelow.ChooseONEWORDONLYfromthepassageforeachanswer.Writeyouranswersinboxes21-26onyourans
Completethesummarybelow.ChooseONEWORDONLYfromthepassageforeachanswer.Writeyouranswersinboxes32-36onyourans
HowdesertsareformedA.Adesertreferstoabarrensectionofland,mainlyinaridandsemi-aridareas,wherethereisal
HowdesertsareformedA.Adesertreferstoabarrensectionofland,mainlyinaridandsemi-aridareas,wherethereisal
TheInnovationofGroceryStoresA.Attheverybeginningofthe20thcentury,theAmericangrocerystoresofferedcomprehen
Whataretheadvantagesanddisadvantagesofsendingthingsbyair?WhenwillthecustomerarriveinCanada?
Whichcolumnofthebarchartrepresentsthefiguresquoted?AstreatmentforbackpaintheClinicmainlyrecommends______.
(With)thediscovery(ofgold)intheKlondikeinCanada’sYukonTerritoryin1896,people(flockedsoon)therefrom(allparts)
随机试题
铸造是一种古老的制造方法,在我国可以追溯到6000年前。随着工业技术的发展,大型铸件的质量直接影响着产品的质量,因此,铸造在机械制造业中占有重要的地位。下列关于铸造工艺操作的说法中,正确的是()。
车辆后轮胎爆裂,车尾会摇摆不定,驾驶人应双手紧握转向盘,控制车辆保持直线行驶,减速停车。
焊缝形式、尺寸和焊接方法只能通过焊缝符号来标注。()
企业在设计销售与收款业务的内部会计控制制度时,销售与收款业务的不相容岗位是指()
APTT测定中除加入白陶土和脑磷脂外,还需加入
薛某拖欠潘某借款5万元,潘某多次催要借款而薛某一直不给。在一次催要过程中,二人发生争执并大打出手,薛某将潘某殴打致伤。区公安分局遂以薛某违反《治安管理处罚法》为由,将薛某行政拘留10天。薛某不服,提起行政复议。复议机关作出复议决定,薛某仍不服,于是向法院提
合规管理部门的基本职责不包括()。
《劳动争议调解仲裁法》规定:劳动争议申请仲裁的时效期间为(),仲裁时效期间从当事人知道或者应当知道其权利被侵害之日起计算。
过程分析和()是一致的。
求幂级数的收敛半径、收敛区间及收敛域,并求收敛区间内的和函数.
最新回复
(
0
)