熱血背包客莊ㄟ

Witnesses to a meteor in Australia in1978 claimed to have heard strange noises as it streaked overhead. Yet, given that the meteor was 30 kilometers up, if these sounds had come directly from the meteor, people on the ground would not have heard them until almost a minute after the meteor had disappeared. Physicist Colin Keay hypothesized that the light given off by a meteor’s trail must accompanied by invisible electromagnetic radiation in the form of very low frequency (VLF) radio waves. Such waves, which travel at the speed of light, would reach the observer when the meteor itself came into view.

Subsequent experiments in a soundproof chamber showed that many things can act as transducers to covert VLF waves into audible vibrations. Aluminum foil, thin wires, pine needles, or dry hair all responded to a VLF field. VLF waves induce small charges in such objects, thereby causing them to vibrate in time with the waves’ oscillation. This transducer effect would explain why some people heard the noises while others close by heard nothing. Those who heard sounds were simply nearer to transducers. It could also explain why attempts to record meteor sounds have failed: scientists carefully set their microphones away from possible sources of interference. 

1.Which of the following best describes the function of the highlighted sentence ?

A. It explains why observers who were looking at the meteor would the only ones who could heard the sounds made as it went overhead.
B. It explains why the witnesses’ claims could not be verified by scientific experts. 
C. It shows that Keay’s hypothesis provides the correct explanation of the sounds heard by observers of the meteor
D. It suggests that Keay’s hypothesis is capable of explaining an important aspect of the witnesses’ observation. 
E. It suggests that Keay’s hypothesis is able to explain how observers can see a fast-moving meteor.

2. The passage suggests that Keay formulated his hypothesis in response to 

A. scientists’s failure to record meteor sounds  
B. an inference based on the speed of sound in the atmosphere 
C. measurements of the strength and wavelength of electromagnetic radiation from a meteor’s trail 
D. the fact that observers who heard meteor sounds were close to objects that could act as transducers of VLF waves 
E. experiments in a soundproof chamber to determine what objects would transduce VLF waves into audible vibrations 

3. It can be infer from the passage that is Keay’s proposed explanation of meteor sounds is correct, it is true that 

A. meteors themselves produce no audible vibrations, even though the meteor dose cause the sounds that observers hear 
B. when an observer hears the sounds, it is his or her own hair that is causing the audible vibrations 
C. if two observers in widely separated locations hear sounds caused by the same meteor, the audible vibrations that reach the observers are produced by different objects.
D. visible light and VLF radio waves are the only forms of electromagnetic radiation that are given off by a meteor’s trail 
E. atmospheric condition, such as clouds, that make a meteor invisible to observers on the ground would also prevent those observers from hearing any sounds caused by meteor

結構分析：

由第一句看完後可以找出主幹是Witnesses to a meteor in Australia in1978 claimed to have heard strange noises as it streaked overhead. 聽到＝看到。然後重點出現在，Yet，這個轉折詞跟however是有點不一樣的，however是楚河漢界，他之前的所有句子講的是同一邏輯，然後他之後的所有句子講的又是另一個邏輯，可是我們的yet他的管轄範圍比較小，代表的是跟上一句話做對比，就是說yet的影響範圍只有前後兩句話而已，在本文就是Witnesses to a meteor in Australia in1978 claimed to have heard strange noises as it streaked overhead. Yet, given that the meteor was 30 kilometers up, if these sounds had come directly from the meteor, people on the ground would not have heard them until almost a minute after the meteor had disappeared，這兩句去做對比，就是說聽到＝看到，轉折（Yet），消失後才聽到（先看到在聽到），然後對比完再另外展開新的發展去跟著開頭邏輯一直持續下去的，所以我們預判，等等第三句應該會講到聽到＝看到這件事

第三句話Physicist Colin Keay hypothesized...導出一個先概念來，very low frequency (VLF)，然而為了知道為何要講VLF我們不得再讀下去，因為他不能證明我們剛剛對文章所做的邏輯預判，所以接下去第四句看，找到VLF=光速，所以大致上可以知道某人說他看到隕石的時候也同時聽到了聲音，但是這違反科學知識啊光速比聲速快多了，所以Ｋ提出假說是因為ＶＬＦ這個東西的關係，他跟光速一樣。

然後第二段Subsequent experiments，看到這兩個字就別看了，因為這很明顯是要對Ｋ所做的假說做支持的動作，因為第二段裡面沒有看到轉折詞，所以整篇文章還是會往聽到＝看到去發展，但不是因為隕石本身的聲音，而是VLF所製造出來的聲音。

第一題：

問到功能題就不是要探討該句的語義，而是該句的用意，開頭有such waves表示代名詞上面的一句話一定有做講述，然後這句才會以代名詞繼續延伸，中間又沒有轉折或負面詞彙，所以可以知道的結果是這句話是支持上一句話，所以把上一句話主幹找到就有答案了，跟做托福的修辭目的題一樣，Physicist Colin Keay hypothesized that the light given off by a meteor’s trail must accompanied by invisible electromagnetic radiation in the form of very low frequency (VLF) radio waves，所以答案剩下（Ｃ）（Ｄ）（Ｅ）可以選，然後主幹要說的是light is accompanied by VLF，（Ｄ）capable對應Ｋ假說，然後an important aspect of the witnesses’ observation. 就是開頭第一句聽到＝看到，對應light is accompanied by VLF，這題出的很隱晦an important aspect等於是要找對文章主旨。選（Ｄ）

補充：

（Ｃ）錯，因為correct explanation of the sounds，這是Ｋ假說，假說是表示可能性猜測，所以就跟『正確解釋』衝突了
（Ｅ）錯，因為how see a fast-moving meteor.這很明顯，文章探討為何會再看到隕石同時聽到聲音，但是選項是探討如何看隕石這差太多了

第二題：

in response to ＝in order to（為了），由結構圖上整個第一段都是在講速度到底一不一樣，所以就選（Ｂ）

第三題：

這只能一個一個看，

（Ａ）no audible vibrations看到這裡就把選項刪除，由結構圖是可以知道整個文章是在說為何看到的時候還聽得到，跟誰發出聲音不關，不是探討主軸。

（Ｂ）his or her own hair 這個如果眼睛夠尖銳的話會發現他在第二段的實驗裡頭的一個小小舉例，這完全犯了以偏概全，而且主角VLF都沒看到

（Ｃ）沒辦法還是要讀一下第二段第一句，本以為不用讀的但是訊息太少無法確定（Ｃ）的正確性，Subsequent experiments in a soundproof chamber showed that many things can act as transducers to covert VLF waves into audible vibrations. 很多東西可以當作傳感器將VLF轉成可聽到的震動波，抓到了，I got you， I got you， I got you ！！many things完美對應選項different objects，在邏輯上假設Ｋ假說是對的，所以Subsequent experiments的東西也是對的，因為這裡都是順向邏輯，沒有任何轉折詞

（Ｄ）的are the only forms of electromagnetic radiation和（Ｅ）的such as clouds都錯得離譜，答案是（Ｃ）

以上個人筆記希望有幫助到大家，有誤再請指教!!