首页
登录
职称英语
What does the passage mainly discuss? [br] [originaltext] Canals are waterc
What does the passage mainly discuss? [br] [originaltext] Canals are waterc
游客
2024-10-11
27
管理
问题
What does the passage mainly discuss? [br]
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、To keep out boats that are too large for the canal.
B、To measure the tonnage of canal boats.
C、To load and unload the cargo.
D、To change the depth of the water.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3797250.html
相关试题推荐
WhatisthepurposeofthemeetinginLuxemburg?[br][originaltext]TheWes
WhatisthepurposeofthemeetinginLuxemburg?[originaltext]TheWesternE
WhichofthefollowingwillNOTpossiblyleadtoheartdisease?[originaltext]
Wheredoestheconversationtakeplace?[originaltext]W:[7]Thisfoodisterribl
ThepeacetalksbetweenrebelsandtheZairiangovernment______.[originaltext]
Whatwillbemosteffectiveaboutpersonalinterviewing?[originaltext]Perso
WhatisJiminterestedin?[originaltext](M=Jim,F=Linda)M:Hello,Linda.F
Today,mostcountriesintheworldhavecanals.Somecanals,suchastheSu
Today,mostcountriesintheworldhavecanals.Somecanals,suchastheSu
Today,mostcountriesintheworldhavecanals.Somecanals,suchastheSu
随机试题
Shewasdeterminednottobecaughtupintheturmoilofhomeagain.Theunderli
Thefollowingisanadvertisement.Afterreadingit,youshouldcompletetheinf
Byreachinganappropriateage(usuallybetween18and21years),1,______c
Accordingtothepassage,howdotoday’speopleforecastweather?Today’speople
Tonyhasnottheleast______ofgivinguphisresearchwork.A、intentionB、intere
能引起外阴瘙痒的原因不包括下列何项A.高血压 B.糖尿病 C.黄疸 D.外
采用分离式配筋的多跨板,板底钢筋宜全部伸入支座;简支板或连续板下部纵向受力钢筋伸
2018年1月1日,S公司拟冲击IPO,于创业板上市,该公司的下列()情况会导
利尿药在心内科使用频率高,高血压、心力衰竭患者常常要用利尿药来治疗。利尿药的种类
(2016年真题)关于概率树分析的说法,正确的有()。A.通常假定输入变量之向
最新回复
(
0
)