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
Biogas: a Solution to Many Problems In almost all developing countries, the lack of adequate supplies of cheap, convenient a
Biogas: a Solution to Many Problems In almost all developing countries, the lack of adequate supplies of cheap, convenient a
admin
2016-11-30
26
问题
Biogas: a Solution to Many Problems
In almost all developing countries, the lack of adequate supplies of cheap, convenient and reliable fuel is a major problem. Rural communities depend largely on kerosene, wood and dung for their cooking and lighting needs. But kerosene is now priced out of reach of many people and wood, except in heavily forested areas, is in short supply. The search for firewood occupies a large part of the working day and has resulted in widespread deforestation.
Dung is in constant supply wherever there are farm animals and, when dried, it is convenient to store and use. But burning dung destroys its value as fertilizer, thus depriving the soil of a much needed source of humus and nitrogen.
Rural areas of developing countries are also plagued by a lack of adequate sanitation. Improper waste disposal spreads disease, contaminates water sources and provides breeding grounds for disease-carrying insect.
The problems of improving environmental hygiene, conserving resources and finding alternative sources of fuel may be unrelated. Their solutions, however, are not, as many countries experimenting with biogas technology are discovering. Biogas, a mixture of methane and carbon dioxide, is produced by the fermentation of organic matter. The process of anaerobic fermentation is a natural one occurring whenever living matter decomposes. By containing the matter—and the process—in a digester or biogas plant, the combustible gas can be trapped and used as fuel for household lighting and cooking. The digested slurry that remains can be used on the land as a soil conditioner and fertilizer.
Biogas plants have attracted much interest in recent years and they are in use in several Asian countries: 36,000 are reported in rural areas of India, 27,000 in Korea and more than 80,000 in China. In most countries the value of the gas has been the prime factor leading to their adoption: 70 per cent of India’s plants, for instance, were built during the energy and fertilizer crisis of 1975—1976— although their use in that country dates back to 1951. Similarly in Thailand and Korea, biogas is being investigated as an alternative to costly charcoal and to save compost materials from being burned.
In Japan and China, reducing pollution from animal wastes has been an important factor. Privies , hen houses and pigpens are built in proximity to the fermentation chamber in China. Examinations of the digested slurry have shown that the total number of parasite eggs was reduced by 93. 6 per cent, hookworms by 99 per cent and no schistosome flukes were found.
The greatest benefits from biogas systems, however, are probably to be derived from the ma-nurial value of the slurry, although it is not widely used outside of India and China. Vegetable farmers near Calcutta found that the digested slurry produced bigger and better tasting peas than did other fertilizers and the weight of root vegetables increased by nearly 300 per cent.
Questions 71 to 75
Complete the summary below with information from the passage, using no more than three words for each blank.
The production of biogas by fermentation of animal and vegetable wastes is a technology that has been largely developed and used in the【E1】____countries. Only very recently have scientists in the industrialized nations begun to show an interest—presumably because of the " energy【E2】____".
Family-sized-biogas【E3】____first came into widespread use in India in the 1950s in an effort to make a cleaner and more efficient use of cattle dung. The programme really expanded in the 1970s, and today there are as many as 100,000 plants throughout the world. Most are in domestic use to provide fuel for plants, but some larger units are operated in order to recycle wastes, supply fertilizer, control pollution and improve【E4】____. One Chinese study has shown that digestion of animal【E5】______in the airtight digesters greatly reduces health hazards from parasitic diseases.
One Indian study has estimated that the value of the fertilizer obtained is in itself greater than the cost of producing the biogas. Thus, the system is economically sound, in addition to other benefits such as a cleaner, healthier environment.
【E2】
选项
答案
crisis
解析
(从题干中的presumably(推测起来,大概)可知,该题属常识推理题。第四段,沼气事实上可以帮助conserving resources and finding alternative sources of fuel,可以猜想工业化国家对沼气感兴趣可能是由于能源危机,即energy crisis。)
转载请注明原文地址:https://kaotiyun.com/show/AuyK777K
本试题收录于:
A类竞赛(研究生)题库大学生英语竞赛(NECCS)分类
0
A类竞赛(研究生)
大学生英语竞赛(NECCS)
相关试题推荐
Becausetheintricatenetworkofthemanydifferentpartsisrequirednotonlyforsupportingandbalancingaheavysuperstructu
SupposeyouweretravellingtoSoutheastAsiaonacruiseship.Youhadsavedupyourallowanceformorethanayearforthetrip
Usually,therearetworeasonstopursueseientifieknowledge:forthesakeoftheknowledgeitself,andforthepracticaluse
A、Apilot.B、Arepairwoman.C、Asuperwoman.D、Awriter.C题目问琳达10岁的时候想成为什么。对话中女士说当她10岁的时候不是很现实但想变得很强大,梦想是成为神奇女侠。故选C。
BushConcernedaboutRisingGasPricesPresidentBushsaysavarietyofglobalforcesaretoblameforcrudeoilpricestopp
Fillinthemissingnumbersinthissequence:15873×7=11111115873×14=22222215873×()=33333315()×28=(
Lookatthedrawing.Thenumbersalongsideeachcolumnandrowarethetotalofthevaluesofthesymbolswithineachcolumnand
Allofthefollowingfourexcept______arethemostfamousdramatistsintheRenaissanceEngland.
PresidentXiJinpingwilltodaybecomethefirstChineseleaderto______theannualWorldEconomicForumintheSwissresortofD
随机试题
事业单位公开招聘工作人员的程序不包括()。
SQLServer2008数据库中,【11】视图是存储一个查询结果的数据库对象。
对脂肪和蛋白质消化作用最强的消化液是()。
A上关、下关、翳风B.三江、承泣、睛明C.大椎、身柱、灵台D.中枢、悬枢、中脘E.二眼、百会、命门治疗犬消化不良、呕吐、泄泻、胃痛宜选
A.龙胆泻肝汤B.五神汤C.济生肾气丸D.阳和汤E.五苓散子痰、脱疽均可服用的方剂是
如图,均匀砂质土壤装在容器中,设渗透系数为0.012cm/s,渗流流量为0.3m2/s,则渗流流速为()。
下列收入来源中,()是股票没有的。
数据库管理系统通常提供授权功能来控制不同用户访问数据的权限,这主要是为了实现数据库的()。
补写出下列名句名篇中的空缺部分。安得广厦千万间,___________,风雨不动安如山。(杜甫《茅屋为秋风所破歌》)
Undermorefavorableconditions,he______agreatgeneralbutheonlyendedupascaptain.
最新回复
(
0
)