首页
登录
职称英语
Today, most countries in the world have canals. Some canals, such as the Su
Today, most countries in the world have canals. Some canals, such as the Su
游客
2023-11-14
20
管理
问题
Today, most countries in the world have canals. Some canals, such as the Suez or the Panama, 【C1】______ 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. 【C2】______ other canals drain lands where there is too much water, help or 【C3】______ fields where there is not enough water.
The 【C4】______ of a canal depends on the kind of boats going through it. The canal must be wide enough to permit two of the 【C5】______ boats using it to 【C6】______ each other easily. It must be deep enough to leave about two feet of water 【C7】______ the keel of the largest boat using the canal. Some canals have sloping sides, while others have sides that are nearly 【C8】______ . Canals that are cut through rock can have nearly vertical sides. 【C9】______ , canals with earth banks may 【C10】______ if the angle of their sides is too steep. Some canals are lined with brick, stone, or concrete to keep the water 【C11】______ soaking into the mud. This also permits ships to go at 【C12】______ speeds, since they cannot make the banks fall in by 【C13】______ up the water. In small canals with mud banks, ships and barges (大平底船) must 【C14】______ their speed.
When the canal goes 【C15】______ different levels of water, the ships must be 【C16】______ or lowered from one level to the other. This is generally done by 【C17】______ of locks. If a ship wants to go up to higher water, the lower end of the lock opens to let the boat in. Then this gate closes, and the water is let into the lock chamber from the upper level. This raised the level of the water in the lock 【C18】______ it is the same as the upper level of water. Now the upper gates can be opened to 【C19】______ the ship into the higher water. Sometimes a canal contains a series of locks when the 【C20】______ in levels is very great. [br] 【C5】
选项
A、largest
B、longest
C、heaviest
D、tallest
答案
A
解析
空前是说运河必须wide enough,由此可推断这里应该是表示可以允许两艘最大的船只很容易地通过,故答案为A largest。
转载请注明原文地址:https://tihaiku.com/zcyy/3185608.html
相关试题推荐
Accordingtotheinternationallyagreedmeasures,poorcountriescan______chea
Tosurviveintheintensetradecompetitionbetweencountries,wemust______th
Whatisveryimportantfordevelopingcountries’economicgrowthaccordingtoth
Whatisveryimportantfordevelopingcountries’economicgrowthaccordingtoth
AccordingtoPakistaniPresident,thechancesofthetwocountriesgoingtowar
Developedcountriestake______oftheworld’shealthexpense.[br][originalte
Developedcountriestake______oftheworld’shealthexpense.[originaltext]
ThefollowingcountriesaretherisingstarsintheaerospaceindustryEXCEPT[b
Whatdoesthepassagemainlydiscuss?[br][originaltext]Canalsarewaterc
Whatdoesthepassagemainlydiscuss?[br][originaltext]Canalsarewaterc
随机试题
Vancouver(温哥华)isacosmopolitan(世界性的)cityofstunningbeauty.Setbetw
水泥中氯离子含量测定的基准方法是()。A.硫氢酸氨容量法 B.磷酸蒸馏-汞盐滴
下列哪项不属于结节性甲状腺肿的手术适应证()A.有压迫症状 B.继发甲亢
A.心肝阴虚 B.心脾两虚 C.心胆气虚 D.心肾阴虚 E.心阴亏虚患者
以下哪项不是先心病患儿术后并发症A.残余分流 B.高心排综合征 C.高血压
以下关于保险人告知方式的表述中,错误的是()。A:明确列明是指保险人只需将保险的
A.下肢关节主动屈伸运动 B.下肢关节被动旋转运动 C.桥氏运动 D.空踩
在右侧的简易示意图中,问号处最可能是: A.华山 B.玉山 C.恒山 D
我国最早的地理学著作《禹贡》,实际上产生于战国后期,但对历史地理现象的注意和记录
应用糖皮质激素出现反跳现象的主要原因包括()A.用量不足 B.用量过大
最新回复
(
0
)