下面给大家带来剑桥雅思9阅读Test3Passage3答案和考题精解，这是一篇关于信息理论information theory的说明文。原文和题目同学们可以到剑桥雅思9阅读答案Test3Passage3考题精解
剑桥雅思9阅读真题答案：
Question 27—32：D、F、B、A、A、C
Question 33—37：Jupiter, Saturn; Solar System、sensors, circuits、spares、radio dish
Passage3整体分析
体 裁 说明文
题 材 科技应用
主 题 介绍信息理论
段落概括 引言 概述信息理论的重要性
A 段 一个信息理论应用的实例
B 段 介绍发明信息技术的工程师Claude Shannon
C 段 Claude Shannon发展这一技术的初衷
D 段 信息交流技术的理论原理
E 段 科学家们就此理论所发展出的各种代码
F 段 Shannon为信息储存所做的贡献
考题精解
Questions 27-32
题型：段落信息配对题MATCHING
解析：此题工作量大，费时多，解题时不建议首选此类试题。在读题过程中把每一个信息句中的主要名词标注出来，到文章每一段中仔细地搜寻。
27.
定位词/关键词explanation of the factors, transmission of information
原文定位D段第四句This rate depends on the relative strengths of the signal and noise travelling down the communication channel, and on its capacity (its 'bandwidth').
题解文章中的communication channel就是信息传递的通道，而relative strengths of the signal and noise就是会影响传递效果的因素，即factors。
答案D
28.
定位词/关键词example, unnecessary information, omitted
原文定位F段第一、二句Shannon also laid the foundations of more efficient ways of storing information, by stripping out superfluous (‘redundant’)bits from data which contributed little real information. As mobile phone text messages like ‘I CN C U’ show, it is often possible to leave out a lot of data without losing much meaning.
题解superfluous bits和contributed little real information都是指unnecessary information;而手机短信的例子对应了题目中的example;leave out替换了题目中的omitted。
答案F
29.
定位词/关键词Shannon's attitude, fame
原文定位B段第四句While at Bell Laboratories, Shannon developed information theory, I but shunned the resulting acclaim.
题解shunned the resulting acclaim意为“回避了最后的称赞”，也就是说他对于名誉的态度很淡薄。
答案B
30.
定位词/关键词details of a machine, interpreting incomplete information
原文定位E段第三句Other codes have become part of everyday life — such as the Universal Product Code, or bar code, which uses a simple error-detecting system that ensures supermarket check-out lasers can read the price even on, say, a crumpled bag of crisps.
题解details of a machine就是此句中超市用的镭射扫描器，而incomplete information就是举例中的破碎的薯片袋子，也就是说即便袋子破损，条形码依旧可以被准确读出。
答案A
31.
定位词/关键词detailed account of an incident
原文定位A段第—句In April 2002 an event took place which demonstrated one of the many applications of information theory. The space probe, Voyager I, launched in 1977 ...
题解此段开头句就直接指明2002年4月发生的事件展示了信息理论的应用，后面又详细地介绍了这一事件的过程。
答案A
32.
定位词/关键词what Shannon initially intended to achieve
原文定位C段第一、二句This all seems light years away from the down-to-earth uses Shannon originally had for his work, which began when he was a 22-year-old graduate engineering student at the prestigious Massachusetts Institute of Technology in 1939. He set out with an apparently simple aim: to pin down the precise meaning of the concept of ‘information’.
题解文中the ... uses Shannon originally had for his work 同义替换了题目中的Shannon initially intended to achieve。下一句话解释了他最初的目的是想确定信息概念的精准信息。
答案C
Questions 33-37
题型：句子填空题SENTENCE COMPLETION
解析：此题是按正序排列的。在每个句子中寻找名词，在文章中锁定位置，然后通过判断空格的词性来选择单词。注意，此题限制字数。
33&34.
定位词/关键词probe, pictures, left
原文定位A段第二句The space probe, Voyager I，launched in 1977, had sent back spectacular images of Jupiter and Saturn and then soared out of the Solar System on a one-way mission to the stars.
题解原文中的images是题目中pictures的替换，再利用of和both ... and ... 的关系可以确定33题的答案。而原文中的soared out of是题目中left 的同义替换，因此其宾语是34题的答案。
答案Jupiter, Saturn; Solar System
35.
定位词/关键词stop working
原文定位A段第四句Sensor and circuits were on the brink of failing and NASA experts realised that they had to do something or lose contact with their probe forever.
题解原文中的on the brink of failing是濒临失去作用的边缘，也就是题目中stop working的同义替换，通过both ... and ... 的关系可以确定答案。
答案sensors, circuits
36.
定位词/关键词replace them with
原文定位A 段第五句 The solution was to get a message to Voyager I to instruct it to use spares to change the failing parts.
题解use sth. to change就是replace的意思。可以把原文中的spares看作A，failing parts看作B，那么原文中就是use A to change B，替换成replace 就是replace B with A，那么A就是答案，即spares。
答案spares
37.
定位词/关键词speed of light
原文定位A 段倒数第二、三句By means of a radio dish belonging to NASA’s Deep Space Network, the message was sent out into the depths of space. Even travelling at the speed of light, it took over 11 hours to reach its target, far beyond the orbit of Pluto.
题解原文中speed of light所在的句子的逻辑主语是后面的it，而这里的it 是指前一句中的方式，也就是means of a radio dish。
答案radio dish
Questions 38-40
题型：判断题 TRUE/FALSE/NOT GIVEN
解析：判断题一般都是顺序的，确定了第一道题的原文定位后，可以向后查找其他题目的答案。特殊情况下会有两道题出自于同一句话的现象。有些题目选NOT GIVEN是因为在文章中无法定位。
38.
定位词/关键词describing something as true or false, starting point for Shannon
原文定位C 段第一至三句This all seems light years away from the down-to-earth uses Shannon originally had for his work ... He set out with an apparently simple aim: to pin down the precise meaning of the concept of ‘information’. The most basic form of information, Shannon argued, is whether something is true or false ...
题解the down-to-earth uses Shannon originally had for his work 就是题目中的 starting point for Shannon。而他最初的目的在下面两句话中进行了详细的解释，即追求precise meaning，信息的最基本形式就是对与错。
答案TRUE
39.
定位词/关键词a given time period, signal strength and noise level
原文定位D段倒数第二句The resulting limit, given in units of bits per second, is the absolute maximum rate of error-free communication given signal strength and noise level.
题解signal strength and noise level是可以在原文中原形定位的，而given time period被替换成了limit, given in units of bits per second。
答案TRUE
40.
定位词/关键词products, more information than Shannon had anticipated
原文定位E 段最后一句As recently as 1993, engineers made a major breakthrough by discovering so-called turbo codes—which come very close to Shannon’s ultimate limit for the maximum rate that data can be transmitted reliably, and now play a key role in the mobile videophone revolution.
题解Products have now been developed同义替换a major breakthrough by discovering so-called turbo codes，Shannon had anticipated as possible 同义替换 Shannon's ultimate limit for the maximum rate，原文说turbo codes非常接近(come very close to)Shannon对最大速率计算的最终极值，而题目说的是其可以传递比Shannon的预期更多的信息。
答案FALSE
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