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
What does the passage mainly discuss?
What does the passage mainly discuss?
admin
2009-01-05
48
问题
What does the passage mainly discuss?
Canals are watercourses constructed to improve and extend natural waterways. They are generally built to facilitate transportation, but from the beginning they have been used for many additional purposes including draining swamps, irrigating land for cultivation, and promoting economic development.
Canals are often classified by the size of vessel they can accommodate. Some small local canals, which are able to float only 100 to 300 ton boats or small rafts of timber, may be only 3 feet deep. Major barge canals generally range from 6 to 9 feet in depth, and some are as much as 10 or 12 feet deep. These canals can carry 1,350 to 2,000 ton craft. Ship canals are 25 feet or more deep and are capable of accommodating large vessels in the seagoing class.
Canals may also be classified as either water level or lock canals. Water level canals do not vary in height a- long their courses. The best known of these is the Suez Canal, which is at sea level. Lock canals, which include most modern waterways, contain locks, or special devices for raising and lowering boats along their courses by changing the depth of the water. Each lock is a stretch of water enclosed by gates at each end. After a boat enters the lock, water is let or drained out until it reaches approximately the same level as the water ahead.
选项
A、modern canal
B、water level canal
C、lock canal
D、irrigation canal
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/7iBK777K
0
专业英语四级
相关试题推荐
Kissing,strokingandwildembracesarecommonenough,andnowthequiet,romanticgestureofholdinghandsinpublicisa【M1】__
ApplicationsoutsidetheEarth’satmosphereareclearlyagoodfitforrobots.Itisdangerousforhumanstogettospace,to
ApplicationsoutsidetheEarth’satmosphereareclearlyagoodfitforrobots.Itisdangerousforhumanstogettospace,to
NewresearchfromtheUnitedStatessuggeststhatthemillennia-oldtherapyofyogacouldbenefitmillionsofpeoplewhosuffe
NewresearchfromtheUnitedStatessuggeststhatthemillennia-oldtherapyofyogacouldbenefitmillionsofpeoplewhosuffe
Thereisnolink,whatsoever,betweentheproducersandusersofmanpowerwiththeresultthatinstitutionsoflearning,essent
Bynow,itshouldcomeasnosurprisewhenscientistsdiscoveryetanothercaseofexperiencechangingthebrain.Fromthesenso
NewdatareleasedtodayfromthePartnershipforaDrugFreeAmericasuggestthatnotonlyaregirlsnowdrinkingmorethanboys
Eveniftheyproducednootherpositiveresult,theattacksontheLondonUndergroundhavecompelledEuropeansofallfaithst
Sherefusedto_________thedoorkeytothelandlorduntilshegotbackherdeposit.
随机试题
医务人员在任何情况下,都能把握自身的不可动摇的一种强有力的内在力量是指一定社会群体或集团的人们,依据一定的道德观念,对社会生活中的事件或人的行为形成的带有倾向性的共同看法,并以此对人的行为或组织施加影响是指
抽样的理论基础是()
怀疑肾动脉狭窄,在诊断时,术前应做哪一项检查最佳
A.清营汤B.凉膈散C.白虎汤D.竹叶石膏汤E.黄连解毒汤
()是资本市场的一个重要组成部分,是生产要素流动和配置的重要载体,也是实现资本要素加快流动和资源合理配置的重要渠道。
关于证券发行的公募发行方式的说法,正确的是()。
拉丁美洲作家________创作的著名小说《百年孤独》是一部魔幻现实主义的作品。
Onafivetothreevote,theSupremeCourtknockedoutmuchofArizona’simmigrationlawMonday—amodestpolicyvictoryforth
下表是PC机中使用的一部分内存条的主要技术参数这四种内存条中数据传输率最高的是
TheU.S.dollarwassupposedtobeattheendofitsrope.Kickingthebucket.Adyingsymbolofadyingempire.Well,maybenot
最新回复
(
0
)