托福听力备考如何提升反应速度?冲高分要这么练
什么是托福听力反应速度?
所谓托福听力反应速度，就是指考生在听到一个单词以后反馈出这个单词意思的速度。这个速度直接决定了考生是否能快速听懂托福听力材料的具体内容，是考生备考听力必须训练的一项基本能力。
为什么要训练托福听力反应速度?
以英语为母语的人在听到一个单词之后的反应速度是0.03秒，我们不是以英语为母语的，所以我们对单词的反应速度可能不能完全达到这个指标，但是尽可能地去接近它，无疑是取得托福听力高分必须做到功课。因为你在听托福听力的时候，ETS不可能等你听明白了前面的单词，然后再放后面的录音，而事实上，托福听力的语速也只是美国大学教授上课的一半语速，所以，不仅为了取得托福高分，更重要的是为了到美国能跟上美国的课堂，我们花大力气将反应速度练上去是完全必要的。
如何训练提升托福听力反应速度?
托福听力备考练习反应速度的最重要也是最有效的一个方法，叫做“变速练习”。变速练习指的是利用变速软件加快语速，来增加我们对材料反应的灵敏度和准确度。但有一点要强调的是，变速练习只适合于对你常速已经可以听懂的材料进行，因为如果对你不熟悉或者本来就听不懂的材料进行变速，那么结果必然是更加听不懂，这样的意义是不大的。明白了这一点，那么你就知道了其实变速练习的材料是十分广泛的，既可以是你已经听写过的听力素材，也可以是SSS的材料，更可以是你已经做过的托福听力题。
2020托福听力练习：最古老靛蓝染料
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."
许多人记得彩虹的颜色按照首字母排列为ROYGBIV。这些首字母分别代表红、橙、黄、绿、蓝、靛、紫。而靛色最近有了新的消息。
靛蓝色得名于木蓝以及其相关植物，这些植物可以提供染料，让布料变成介于蓝色和紫色之间的一种富贵、美丽的颜色。
靛蓝染料在古代用于对布料进行染色，而这些布料一般产自埃及、中国、中美洲以及南美洲等地方。最近，研究人员就在南美洲发现了目前已知最古老的靛蓝染色布料。
人们在普雷塔遗址发现了这些手工艺品，普雷塔遗址位于秘鲁北部海岸，是一个曾用于举行仪式的土丘。但是这些手工艺品的颜色最初被灰色基调所掩盖，而灰色来自于土堆本身材料的渗透。但是，当一位文物修复员仔细清理这些布料后，其真正的颜色重新显现出来。
“就在那时我意识到，我们发现的可能是是靛蓝色，而且这可能是世界上最古老的靛蓝色。”
杰弗里·斯皮里特瑟是乔治华盛顿大学的人类学家。
“这太让人兴奋了。我在做这个项目的时候，从来没想过我或者说我们会发现世界上最古老的靛蓝色。”
这项研究发表在《科学进展》期刊上。
这块染色布料大约有6000年的历史。
约公元前3100年，在中东有讨论蓝色布料的铭文。虽然这些只是文字材料。不过，我们认为它们指的可能是最古老的靛蓝色纺织品。因此，靛蓝色染料的历史可追溯到5000年前，即大约公元前3100年。而这些新发现的染色布料至少要早1000年。此前已知最古老的靛蓝色纺织品来自于古埃及，距今大约4400年。所以，新发现的染色布料比那些要早约2000年。
斯皮里特瑟表示，这一发现表明，美洲发明将布料染成蓝色的技术很可能早于埃及。
“这实际上意味着，我们必须将古安第斯地区视为世界上织物创新最早的起源地之一。”
重点讲解：
1. take on 承担，接受(尤指艰巨工作或重大责任);
例句：He is ready to take on heavy responsibilities.
他乐于承担重担。
2. refer to 提到，指的是;
例句：It can refer to an academic subject or a practical skill.
这一词既可指某一学科也可指某种技能。
3. at least (数量)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，可可树至少已有了三百万年的种植历史。
2020托福听力练习：道路噪音与鸟类生存
It's hard to be a bird in our human-dominated world.
You can barely hear yourself sing, let alone hear the songs of your friends… and you can forget about hearing a predator. Noise is almost everywhere. Especially noise from traffic. A whopping 83 percent of the surface of the continental U.S. is within just one kilometer of a road.
Researchers have tried to assess the impact of road noise on animals by, understandably, looking at animals living near noisy roads. The problem is that noisy roads are both noisy, and well, they're roads. It's hard to separate the two.
"And so we figured out a way to have just the noise without any of the other effects of the road, and to do that we ran speakers through a forest where there was no road."
Chris McClure, a biologist at Boise State University and The Peregrine Fund. He and his team built their audio phantom road at a popular stopover site for birds in Idaho as they fly south for the winter.
While the noise kept lots of birds away, some stuck around. But they had trouble putting on enough weight to fuel the next leg of their migratory journey.
"They have to fatten up but they also have to not get eaten by a predator. And those two things are in conflict. Because to eat, they have to look down, which means they aren't looking at predators."
And when it's too loud, they can't hear the alarm calls of other birds. So they have to waste time looking for predators instead of foraging. The study is in the journal Animal Conservation.
By 2050, it's thought that enough new roads will be built to circle the planet more than 600 times. But there's an easy solution to the noise problem.
"Lowering speed limits does a lot."
So next time you're driving through nature, just slow down a little. It's safer for you and the wildlife. And you can enjoy the view a little longer.
在我们人类主宰的世界里，鸟类的生存很艰难。
你几乎听不到自己唱歌，更别提你朋友们的歌声了……你也可能会忘掉听到的捕食者的声音。因为噪音无处不在。尤其是交通嗓音。高达83%的美国大陆表面仅仅有一公里的路。
研究人员试图评估道路噪音对动物的影响，可想而知，他们的方法就是观察生活在嘈杂道路附近的动物。问题是，嘈杂的道路虽然十分吵闹，但同时也是道路。所以很难把道路与噪音区分开。
“因此，我们想出了一个方法只测试噪音的影响，而不受道路的影响，为了做到这一点，我们把扬声器铺满没有道路的树林。”
克里斯·麦克卢尔是来自博伊西州立大学和游隼基金会的生物学家。他和他的团队在爱达荷州一个鸟类喜欢的停留地建立了“声音幽灵路”，鸟类在飞往南方过冬时喜欢停留在那里。
虽然噪音使很多鸟远离这里，但是也有一些仍然逗留在附近。不过，由于它们无法增加足够的体重，所以它们没有动力飞到迁徙途中的下一个停留地。
“它们必须要吃东西，可是它们也要小心不被捕食者吃掉。这两者相互矛盾。因为，要吃东西，它们就必须低头觅食，可是这样一来它们就不能观察捕食者了。”
当嗓音过大时，它们听不到其他鸟类发出的警报声。所以，它们必须花时间寻找捕食者，这样它们就不能觅食。这项研究发表在《动物保护》期刊上。
预计到2050，新建道路可绕地球超过600次。但是却没有简单的方法能解决噪音问题。
“降速限制可以降低噪音。”
所以，下一次你开车穿过大自然时，可以把速度放慢点儿。这样做对你和野生动物来说更加安全。而且你也有更多的时间可以享受美景。
重点讲解：
1. let alone (通常用在否定句后)遑论，更别提，更不用说;
例句：They had never seen such massive equipment, let alone made.
这样的大设备他们看都没看过，更不用说制造了。
2. figure out 想出;理解;弄清;
例句：We must figure out how to do it.
我们必须想出做这件事的办法。
3. stick around 呆在原处(等待);
例句：Stick around a while and see what develops.
呆上一会儿，看看会发生什么。
4. instead of 代替…;而不是…;
例句：I have to finish my work instead of going out.
我必须完成工作，不能外出。
5. slow down (使)放慢;(使)减速;
例句：When the light is yellow, you should slow down.
灯变黄色时,你应该减速。
