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
Municipal sewage is of relative]y recent origin as a pollutant. It was first brought to public attention in the 19th century by
Municipal sewage is of relative]y recent origin as a pollutant. It was first brought to public attention in the 19th century by
admin
2010-02-17
96
问题
Municipal sewage is of relative]y recent origin as a pollutant. It was first brought to public attention in the 19th century by a London physician who showed that the city’s cholera outbreak had been caused by just one contaminated well. Even though the contamination of drinking water by disease germs has been nearly eliminated in this country, hundreds of communities are still discharging raw sewage into streams and rivers.
When we consider that this sewage contains effluents from toilets, hospitals, laundries, industrial plants, etc. , then the potential of the pollutants as a health hazard is apparent.
The problem of municipal sewage disposal is complicated by the fact that, years ago, most cities combined their storm and waste disposal sewers. Many of these combined systems work well, but others cannot cope with sudden heavy rains. When such storms occur, water mixed with sewage may flood and disable treatment plants unless bypassed, untreated, into a stream. In either case; the people may have little protection for several days from these wastes that may contain disease germs.
Even if adequately treated to eliminate the health hazard, sewage is aesthetically undesirable because of odors and colors produced. Detergents have posed a particular disposal problem. Although there is no indication that they are injurious to health, they can cause foaming, which can clog treatment plants and, at the least, spoil the scenic beauty of streams.
Rural and suburban residents should be aware that septic tanks and cesspools are a potential source of pollution to ground water supplies. This is especially true in the suburban areas with a high population density and with
no municipal sewage disposal and treatment system available. In some areas, sewage disposal is accomplished by cesspools. Soil research is furnishing guidelines for more effective and safer use of systems such as these.
In densely populated suburban areas, a danger exits from ______.
选项
A、streams that do not flow directly to open bodies of water
B、cesspools and septic tanks that contaminate water supplies
C、storm and waste disposal sewers that have been combined
D、the undesirable odors of sewage
答案
B
解析
此题为细节题。答案在最后一段的主题句中。线索词为“suburban”、“source of pollution”和“ground water”。
转载请注明原文地址:https://kaotiyun.com/show/pI9K777K
0
专业英语四级
相关试题推荐
Somepeoplebelievethatinternationalsportcreatesgoodwillbetweenthenationsandthatifcountriesplaygamestogetherthe
Weallhaveoffensivebreathatonetimeoranother.Inmostcasesoffensivebreathemanatesfrombacteriainthemouth,althoug
AircraftCarriersareapowerfulandextremelyflexiblepartofanation’sdefense./Acarderisflexibleinawaythatarmiesa
Thereareagreatmanycareersinwhichtheincreasingemphasisisonspecialization.Youfindthesecareersinengineering,in
TheCarnegieFoundationreportsaysthatmanycollegeshavetriedtobe"allthingstoallpeople".Indoingso,theyhaveincre
Theathleticprogramisexpectedtobringpublicitytotheschool,attractstudents,fosterstudentunity,andencouragealumni
Theathleticprogramisexpectedtobringpublicitytotheschool,attractstudents,fosterstudentunity,andencouragealumni
What’stheplanGM’sCEOannouncedattheautomaker’sannualshareholdersmeeting?
Ofallthingsintheworld,Imostdislikefillingupforms;infact,Ihaveapositivehorrorofit.Applyingforadrivinglic
3.______wehaveachievedisattributedtotheguidanceofourparents.
随机试题
SuggestopediaIntroductionbasis:how【L1】________worksandhowwelearnmosteffectivelyorigin:【L2】________andpedagogy
简述我国现代化建设“三步走”的战略的主要内容。
手术病人术前12小时禁食、4小时禁水的理由是【】
按《建筑地基基础设计规范》(GB50007—2002),可采用( )测定土的抗剪强度指标。
可逆流操作的换热器种类较多,当需要的传热面积不太大而要求的压强较高传热效果较好时,宜选用()。
下列属于通用会计核算软件的特点是()。
国外厂商后来补换30台多媒体设备进口,申报进口时,报关单“贸易方式”栏应填()。该批设备进口报关申报时,应向海关提交的单证为()。
读我国某区域图,阴影表示某种地理事物的过渡地带。据此回答下列问题。图中阴影与我国的哪条地理分界线基本相符合?()
西子湖:曹娥江
Whatisthefundamentalthingthatdrivesstockprices?______.
最新回复
(
0
)