托福聽力講座4條解題原則分享 ,應(yīng)對難題更輕松。今天小編給大家?guī)硗懈Ｂ犃χv座4條解題原則分享 應(yīng)對難題更輕松，希望能夠幫助到大家，下面小編就和大家分享，來欣賞一下吧。

托福聽力講座4條解題原則分享 應(yīng)對難題更輕松

1、主旨題找線索遵循首尾原則

眾所周知，絕大多數(shù)講座的行文方式都是由教授開門見山地講述通篇的主旨，所以針對主旨題必須聽明白的就是首段了。結(jié)尾方式則比較多樣化，時而首尾呼應(yīng)，時而深化主題，甚至有的時候會出現(xiàn)一些和開始不一致或者相反的結(jié)論，這時主旨題的正確選項則應(yīng)該從結(jié)尾處對應(yīng)獲得。

2、文章結(jié)構(gòu)題按照順序原則記重點(diǎn)

一般來講，如果聽到類似基數(shù)詞“one, two, three”，或者序數(shù)詞“first, second, third”，亦或像邏輯順序詞“to start off, to begin with, and, another, also, something else”。還有“yet another, last but not least, that’s when the concept of X comes into the picture”之類的信息，那么這篇講座的結(jié)構(gòu)一般就可以被輕松地定性為是“總分結(jié)構(gòu)”，而且考生應(yīng)該了解，所有上述的提示詞之后必定會出現(xiàn)一個分論點(diǎn)，必須做記錄，因為對應(yīng)會考查細(xì)節(jié)題。

3、推斷題必須把握好定義原則

一旦文章當(dāng)中出現(xiàn)了針對某個詞或者某個概念的定義性解釋，那么這個被解釋的詞或者概念一定我們筆記的重中之重。因為這個詞對于大多數(shù)考生來說往往是一個完全陌生的概念，而且對這個詞的理解程度很可能會直接影響我們對整篇文章的理解程度，因為文章的其它部分或許就是因為這個概念而展開的。很多推斷題就是基于某個定義而考查的。

4、細(xì)節(jié)題請重視舉例原則

平時生活中我們舉例子的目的就是為了用一個具體的實(shí)例去解釋抽象的概念，在托福聽力中也不例外。那么大家除了要聽到“for instance, let’s take X as an example”這類短語，還要留意諸如“say, it can, one typical” 這類詞，而且一定要知道這些實(shí)際的例子到底是為了解釋哪個抽象的概念才存在的，也就是說，一定要找出分論點(diǎn)和細(xì)節(jié)之間的對應(yīng)關(guān)系，切勿犯了張冠李戴的錯誤。題目方面可以設(shè)置成：在題干中給出分論點(diǎn)，要求選出對應(yīng)細(xì)節(jié)的細(xì)節(jié)題;也可以設(shè)置成，在題干中給出細(xì)節(jié)，要求選出對應(yīng)分論點(diǎn)的組織結(jié)構(gòu)題。

2020托福聽力練習(xí)：聚焦節(jié)能的白光發(fā)明

LEDs use only a quarter the energy of incandescent bulbs. But despite their efficiency, there is one thing they're not that good at: "They have a hard time giving directional light." Sangam Chatterjee, a physicist at the University of Marburg and the University of Giessen, in Germany.

Chatterjee and his colleagues may have fixed that. They devised a highly focused, but still energy-efficient light beam, by starting with something that's already a highly focused beam: a laser. The key is what they shoot the laser at: a substance with a particular structure. "I'm always tempted to say "white powdery substance" but I guess there's some connotation on that."

They synthesized the material from cages of tin and sulfur atoms decorated with hydrocarbon molecules. The laser-produced infrared light — which the human eye cannot see — goes in, but what comes out are many different optical wavelengths. "It's a molecular light converter. It basically changes the color of the light, while retaining the directionality of the lasers. So you can make something like a white laser beam containing many, many colors." That mix of colors, overall, glows bright white, like a halogen bulb in a beam. The study is in the journal Science.

This sort of low-energy focused white beam could be used for the very small — like a light source for microscopes — to the very big. "You could use this for a spotlight in the theater. And in the end it should be much more energy efficient than the typical standard spotlight." Meaning focused white light…that takes a little heat off the environment.

LED燈使用的電量僅為白熾燈的1/4。雖然LED燈高效節(jié)能，但是它們也有不擅長的事情：“它們不能發(fā)射平行光?！鄙Ｙつ贰げ樘丶堑聡R爾堡大學(xué)和吉森大學(xué)的物理學(xué)家。

查特吉和他的同事可能已經(jīng)解決了這個問題。他們通過高度聚焦的光束——激光，發(fā)明了一種高度聚焦且節(jié)能的光束。關(guān)鍵就是用激光照射一種擁有特殊結(jié)構(gòu)的物質(zhì)。“我一直想說是白色粉狀物質(zhì)，不過我想關(guān)鍵是內(nèi)部的東西。”

他們用烴分子修飾的錫和硫原子合成了這一材料。激光發(fā)出的紅外線肉眼看不到，紅外線進(jìn)入后會產(chǎn)生很多不同的波長。“這是一種分子光轉(zhuǎn)化器。可以改變光的顏色，但同時保留激光的方向性。這樣就可以制造出含有很多種顏色的白色激光束。”混合的顏色就會發(fā)出像鹵素?zé)襞菀粯拥牧涟咨馐?。這一研究結(jié)果發(fā)表在《科學(xué)》雜志上。

這種低能聚焦白色光束既可以應(yīng)用于顯微鏡光源這種小物件上，也可以應(yīng)用到大場合。“這種光束可以用作劇院的聚光燈。比普通的標(biāo)準(zhǔn)聚光燈更加節(jié)能。”這表明聚焦白光可以消耗環(huán)境中的一部分熱量。

謝謝大家收聽科學(xué)美國人——60秒科學(xué)。我是克里斯托弗·因塔利亞塔。

重點(diǎn)講解：

1. be good at 擅長的;精通的;能干的;

例句：He is good at mental arithmetic.

他擅長心算。

2. start with (以做某事) 開始;

例句：I wanna start with a song that means a lot to me.

我打算由一首對我意義非凡的歌開始。

3. be tempted to do sth. 想做…的;希望做的;

例句：I was sorely tempted to complain, but I didn't.

我極想發(fā)牢騷，但還是沒開口。

4. in the end 最終;

例句：He debated buying a new car, but didn't in the end.

他思量很久是否買輛新汽車，但最后還是沒買。

2020托福聽力練習(xí)：樺樹在夜晚進(jìn)入睡眠

This is Scientific American — 60-Second Science. I'm Cynthia Graber.

Many people remember the colors of the rainbow by the acronym ROY G. BIV. For red, orange, yellow, green, blue, indigo and violet. Well, the color indigo just made news.

Indigo gets its name from the plant Indigofera tinctoria and its relatives, which supply the dye that makes fabric the rich, beautiful color between blue and violet.

Indigo dye was used around the ancient world in fabrics created from Egypt to China to Meso and South America. And it's in South America that researchers recently found the oldest known example of fabrics dyed with indigo.

The artifacts were discovered at Huaca Prieta, a ceremonial mound on the coast in northern Peru. But their color was initially hidden by the grey tones that had leached into them from the materials used in the mound itself. But when a conservator carefully washed the fabric, the true colors reappeared.

"And it was at that point that I realized we probably had indigo and it was probably the world's oldest indigo."

Jeffrey Splitstoser, an anthropologist at George Washington University.

"Which was really exciting. I hadn't thought I'd be discovering, or we would be discovering, the world's oldest indigo, when I took on this project."

The research is in the journal Science Advances.

The dyed fabric is about 6,000 years old.

"In the Middle East there are inscriptions that discuss blue fabrics that date to about 3100 B.C. These are just texts though. And so we think they're referring probably to the earliest Old World indigo-blue dyed textiles. So that would date to about 5,000 years ago, 3100 B.C. And so these are at least 1,000 years older than that. And the earliest known indigo blue textiles were from Egypt and they date to around 4400 B.P., before present. So these are almost 2,000 years older than those."

Splitstoser says that the discovery means it's likely that the techniques to dye fabric blue were developed in the Americas before they were developed in Egypt.

"It really means that we have to look at the ancient Andes as one of the earliest sources of textile innovations in the world."

許多人記得彩虹的顏色按照首字母排列為ROYGBIV。這些首字母分別代表紅、橙、黃、綠、藍(lán)、靛、紫。而靛色最近有了新的消息。

靛藍(lán)色得名于木藍(lán)以及其相關(guān)植物，這些植物可以提供染料，讓布料變成介于藍(lán)色和紫色之間的一種富貴、美麗的顏色。

靛藍(lán)染料在古代用于對布料進(jìn)行染色，而這些布料一般產(chǎn)自埃及、中國、中美洲以及南美洲等地方。最近，研究人員就在南美洲發(fā)現(xiàn)了目前已知最古老的靛藍(lán)染色布料。

人們在普雷塔遺址發(fā)現(xiàn)了這些手工藝品，普雷塔遺址位于秘魯北部海岸，是一個曾用于舉行儀式的土丘。但是這些手工藝品的顏色最初被灰色基調(diào)所掩蓋，而灰色來自于土堆本身材料的滲透。但是，當(dāng)一位文物修復(fù)員仔細(xì)清理這些布料后，其真正的顏色重新顯現(xiàn)出來。

“就在那時我意識到，我們發(fā)現(xiàn)的可能是是靛藍(lán)色，而且這可能是世界上最古老的靛藍(lán)色?！?/p>

杰弗里·斯皮里特瑟是喬治華盛頓大學(xué)的人類學(xué)家。

“這太讓人興奮了。我在做這個項目的時候，從來沒想過我或者說我們會發(fā)現(xiàn)世界上最古老的靛藍(lán)色?！?/p>

這項研究發(fā)表在《科學(xué)進(jìn)展》期刊上。

這塊染色布料大約有6000年的歷史。

約公元前3100年，在中東有討論藍(lán)色布料的銘文。雖然這些只是文字材料。不過，我們認(rèn)為它們指的可能是最古老的靛藍(lán)色紡織品。因此，靛藍(lán)色染料的歷史可追溯到5000年前，即大約公元前3100年。而這些新發(fā)現(xiàn)的染色布料至少要早1000年。此前已知最古老的靛藍(lán)色紡織品來自于古埃及，距今大約4400年。所以，新發(fā)現(xiàn)的染色布料比那些要早約2000年。

斯皮里特瑟表示，這一發(fā)現(xiàn)表明，美洲發(fā)明將布料染成藍(lán)色的技術(shù)很可能早于埃及。

“這實(shí)際上意味著，我們必須將古安第斯地區(qū)視為世界上織物創(chuàng)新最早的起源地之一?！?/p>

重點(diǎn)講解：

1. take on 承擔(dān)，接受(尤指艱巨工作或重大責(zé)任);

例句：He is ready to take on heavy responsibilities.

他樂于承擔(dān)重?fù)?dān)。

2. refer to 提到，指的是;

例句：It can refer to an academic subject or a practical skill.

這一詞既可指某一學(xué)科也可指某種技能。

3. at least (數(shù)量)至少，不少于;

例句：Cacao has been cultivated for at least three millennia in Mexico, Central and South America.

在墨西哥及中南美洲，可可樹至少已有了三百萬年的種植歷史。