首页
登录
职称英语
[originaltext] Today, most countries in the world have canals. Even in the 2
[originaltext] Today, most countries in the world have canals. Even in the 2
游客
2023-09-12
65
管理
问题
Today, most countries in the world have canals. Even in the 20th century, goods can be moved more cheaply by boat that any other means of transport. Some canals such as the Suez or the Panama, save ships weeks of time by making their voyage a thousand miles shorter. Other canals permit boats to reach cities that are not located on the coast. Still other canals drain lands where there is too much water, help to irrigate fields where there is not enough water.
In places where it does not rain very often, irrigation canals drain water from rivers or lakes such as the lake behind the Aswan Dam on the Nile River, and provide the irrigation water.
In places where there is too much water, canals can drain the water off the land for use in fanning. In Holland, acres and acres of land have been drained in this way. Since much of this drained land is below sea level, the water in the canals has to be pumped up to sea level. Dikes have been built in Holland to keep the sea from covering the land, as it did in the past.
Canals are also used to carry water to mills and factories. The water from a river is kept at a higher level than the river until it reaches the wheel of the mill. Then the water is poured over un61 it reaches the wheel of the mill. Then the water is poured over the mill wheel, making it turn. The same principle is used in more modern factories and in hydroelectric generating plants. The force of the water, falling from a certain height, provides a cheap way of producing electricity.
选项
A、Cheaper and sometimes faster.
B、More expensive, but faster.
C、Cheaper. but more dangerous.
D、Moro expensive and slower.
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3006983.html
相关试题推荐
[originaltext]Ithasbeenofficiallyacknowledgedthattheincomegapisa
[originaltext]Ithasbeenofficiallyacknowledgedthattheincomegapisa
[originaltext]ExpertssaysomefarmingactivitiesareseriouslydamagingEa
[originaltext]Yearsagobeforetherewererefrigerators,anicehousewasa
[originaltext]W:Somanypeoplefeartotalkaboutdrugs.Soprofessor,wouldy
[originaltext]W:Somanypeoplefeartotalkaboutdrugs.Soprofessor,wouldy
[originaltext]ThecolorfulInternetdrawsustocomputersandbringsusjoy
[originaltext]ThecolorfulInternetdrawsustocomputersandbringsusjoy
[originaltext]ThecolorfulInternetdrawsustocomputersandbringsusjoy
[originaltext]W:Hello,John,youmustbepleased.Afterall,howmanystudents
随机试题
Theteacher______hisstudentsthinkhighlywaseducatedfromBeijingUniversit
July7th,2009DearProf.Lee,TheAcademicConferenceontradi
A.whileB.darkC.devisedD.whereasE.specificF.agreeableG.regul
Suicidehasbeenacauseofconcerninmostsocietiesforalongtime.Thec
强调心理和行为的整体性是()心理学的主要特点。A.机能主义 B.格式塔
车辆检测器产品外观及安装质量检测和主要技术指标检测中任一项不符合要求时,该项扣分
简述影响问题解决的因素。
患者,女,26岁,主诉:近半年来全口牙龈逐渐肿大,刷牙易出血,有自发性出血史。
下列属于无形资产的是()。A、经营权.专利权.特许权 B、租赁权.专利权.土
癫痫持续状态判断的标准之一,是指一次发作的时间至少超过A.30分钟 B.25分
最新回复
(
0
)