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
Each year, millions of people in Bangladesh drink ground water that has been polluted by naturally high levels of arsenic poison
Each year, millions of people in Bangladesh drink ground water that has been polluted by naturally high levels of arsenic poison
admin
2012-10-23
55
问题
Each year, millions of people in Bangladesh drink ground water that has been polluted by naturally high levels of arsenic poison. Finding safe drinking water in that country can be a problem. However, International Development Enterprises has a low-cost answer. This non-governmental organization has developed technology to harvest rainwater.
People around the world have been harvesting rainwater for centuries. It is a safe, dependable source of drinking water. Unlike ground water, rainwater contains no minerals or salts and is free of chemical treatments. Best of all, it is free.
The rainwater harvesting system created by International Development Enterprises uses pipes to collect water from the tops of buildings. The pipes stretch from the tops of buildings to a two-meter tall storage tank made of metal. At the top of the tank is a so-called "lust-flush" device made of wire screen. This barrier prevents dirt and leaves in the water from falling inside the tank.
A fitted cover sits over the "first-flush" device. It protects the water inside the tank from evaporating. The cover also prevents mosquito insects from laying eggs in the water.
Inside the tank is a low coat plastic bag that collects the water. The bag sits inside another plastic bag similar to those used to hold grains. The two bags are supported inside the metal tank. All total, the water storage system can hold up to three-thousand-five-hundred liters of water. International Development Enterprises says the inner bags may need to be replaced every two to three years. However, if the bags are not damaged by sunlight, they could last even longer.
International Development Enterprises says the water harvesting system should be built on a raised structure to prevent insects from eating into it at the bottom. The total cost to build this rainwater harvesting system is about forty dollars. However, International Development Enterprises expects the price to drop over time. The group says one tank can provide a family of five with enough rainwater to survive a five-month dry season.
Which of the following actually prevents dirt and leaves from falling inside the tank?
选项
A、a barrier
B、a wire screen
C、a first-flush
D、a storage tank
答案
B
解析
第三段最后两句At the top of the tank is a so-called “first-flush” device made of wire screen.This barrier prevents dirt and leaves in the water from falling inside the tank。水箱上面有一个所谓的first-flush的装置,是用铁丝网做的。这一屏障能防止雨水中灰尘和树叶掉落到水箱中。题干中actually“到底”一词很关键,据此可排除C选项,而选出B。
转载请注明原文地址:https://kaotiyun.com/show/Ob9O777K
0
考博英语
相关试题推荐
She______becauseshefoundthejournalinteresting.
Deathcomesquicklyinthemountains.Eachwinterholidaymakersarecaughtunawaresastheyhappilyskiawayfromthefixedrun
Ithinkifishightimewe______thefactthatenvironmentalpollutioninthisareaisgettingmoreseriousthanbefore.
Distanceeducationisenrollmentandstudywithaneducationalinstitutionthatprovideslessonmaterialspreparedinasequenti
AccordingtoRyle,thetaskofphilosophyistorestate______"misleadingexpressions"informsthatarelogicallymoreaccurat
AnaisNin’sdiariesareoftenscandalous,probablybecauseshedescribesherselfassheisratherthan______.
Thisspecialcommitteewasestablishedforwell-integratedmembersofthesocietyandnotfor______individuals.
Justiceinsocietymustincludebothafairtrialtotheaccusedandtheselectionofanappropriatepunishmentforthoseproven
HehadaconsiderablereputationinEnglandasacriticandwasthe______exponentinthiscountryofmodemFrenchliterature.
Mostofthemhadvisitedtheinvalidoftenduringthepastfewmonths,marvelingathis______spiritandhisunfailinggoodtem
随机试题
港口设施维护工程预算辅助表格可包括()。
Lookingup,Isawhereyesfixedonmein______(curiously).
甲公司将一幢别墅无偿赠与某希望小学,根据税法的规定,甲公司应当缴纳何种税:()
【2018年第15题】砌体结构的高厚比限值与下列哪项无关?
()是物业管理法律规范在调整物业管理及相关活动的过程中所形成的法定权利义务关系。
岭南“四大园林”,分别是()。
人事小组的测评成员不包括()。
一个不爱上课的学生还能认真听讲,使其做到这一点的注意类型是
属于《宪法》中既是义务又是权利的是()
设α~β(x→a),则等于().
最新回复
(
0
)