题目内容
12.Cables are playing a very important part in today's communicates.They have been in use for over 100 years,but in the early times they caused a lot of difficulties for the forerunners.Clearly,messages can be sent across the land by means of the
electric telegraph,but you cannot put up a line of telegraph posts across
the sea.Messages can be sent across the ocean by radio or by cable.
The cable lies on the sea bottom and it has to have very good insulation
(绝缘).If any part of it is weak,the water will get through and stop all signals.
The first cable under the sea was between England and France.It was laid in 1851.In 1851 engineers tried to lay cable across the Atlantic Ocean,but they met a lot of diffidently.Half way accrues the Atlantic the cable broke,and the ship that was laying it had to return.
Kelvin advised that another cable ought to be laid.It was mad mady and put on board a big ship.Kelvin and his friends traveled with it and after many days of hard work,they reached America without breaking the cable.Keivin himself sent the first message by cable from America in Britain.Unfortunately only 732 messages were sent through this cable before it broke.
The next cable was laid in 1866,and this time there were no problems.The ship that laid it was the Great Eastem,one of the strongest ships that time there were no problems.The ship that laid it was the Great Eastern,one of the strongest ships that have ever been built.On the other hand,it was driven by powerful engines and also by sails.
60.The undersea cable must be made strong enough to preventC.
A.fishes from eating it
B.enemy stealing it
C.water getting through it
D.others cutting it
61.The undersea cable that Kelvin and his friends laid was betweenB.
A.England and France
B.America and England
C.America and France
D.England and Britain
62.This passage mainly tells usC.
A.how Kelvin laid the cable
B.how the scientists discovered the cable
C.the history of the cable in the world
D.how do lay the cable in the sea.
分析 本文属于说明文阅读,作者通过这篇文章主要向我们描述了当今通信起着非常重要的作用的电缆的发展历史,海底电缆的成功建立更是经历了许多的困难,它必须坚固到水绝对不能进入,建立十分困难.
解答 60.C.细节理解题.根据文章第一段"If any part of it is weak,the water will get through and stop all signals"可知底电缆必须坚固到足以防止水进入它以免截断信号;故选C.
61.B.细节理解题.根据文章第三段"Keivin himself sent the first message by cable from America in Britain"可知欧凯文和他的朋友交流的海底电缆是在英国和美国之间;故选B.
62.C.主旨大意题.通读全文,可知文章主要讲了当今通信起着非常重要的作用的电缆的发展历史,海底电缆的成功建立更是经历了许多的困难,它必须坚固到水绝对不能进入;故选C.
点评 考察学生的细节理解和推理判断能力,做细节理解题时一定要找到文章中的原句,和题干进行比较,再做出正确的选择.在做推理判断题不要以个人的主观想象代替文章的事实,要根据文章事实进行合乎逻辑的推理判断.
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