精彩演讲视频
The Undera
World of Soundowada
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Snorts, clicks, groans – tune in to the long-distance language of the ocean
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A The vast oceans of the world are dark, deep and mysterious places where eyesight counts for little as soon as you venture very far beneath the surface.
B For humans, who live in a world dominated by visual stimuli, to exist in such conditions would be impossible. But for whales and dolphins that live in the ocean or, in the ca of a few species, muddy rivers and estuaries, the darkness is unimportant. just nowWhat is crucial to them is sound.
C Sound is an efficient way to transmit and n information, especially as it travels five ti
mes faster through water than through air. behalfIf humans shout to someone, it is unlikely that they will be heard a kilometer away. But if a whale ‘shouts’ in an ocean channel, another whale may hear it tens, if not hundreds, of kilometers away.
D Whales and dolphins u sound in two ways: for communication and for echolocation. Dolphins, porpois and toothed whales communicate through a wide variety of high-frequency sounds – pure tone whistles, puld squeals, screams or barks – generally at frequencies of 500Hz to 20kHz (where a hertz is a cycle per cond and a kilohertz a thousand).
E But as well as using sounds to communicate, toothed whales and dolphins also rely on echolocation to learn about their immediate environment, including prey that might be lurking nearby. They produce inten short broad-band puls of sound in the ultrasonic range of between 0.25 and 220 kHz. The clicks are brief – typically less than one millicond long- but they are repeated many times each cond.
1. Write two ntences that summari the passage.
影视推荐2. What is the writer’s main purpo in this passage?
A, to explain the function of whale and dolphin sounds
B. to account for the development of underwater sounds
C. to compare the sounds made by whales and dolphins
D. to give the results of his studies on underwater sounds
IELTS Reading test practice ___________ Finding information in paragraphs
The Undera World of Sound passage has five paragraphs A-E.
Which paragraph contains the following information?
1 a contrast between the speed of sound in and out of the ocean
2 a reference to hoe whale and dolphin nois can help them find food
3 a description of what it is like under the a
4 the names of a range of nois whales and dolphins make underwater
5 the various places whales and dolphins can be found
IELTS Reading test practice ___________ Choosing headings for paragraphs
Choo the correct heading for each paragraph from the list of heading below.
List of Headings
i Increasing customer confidence
ii A benefit retailers
iii The bigger picture of how internet u changes consumer behaviour
iv Introducing a novel approach to purchasing
tingclassv The dangers for detailers
vi Retraining staff
vii Changing the face of the shop and the internet site
viii A look at the sales figures
ix Encouraging online feedback from consumers
wily, Wired Consumers研究生英语听说教程
tunnel
The Internet has empowered shoppers both online and offline.
A The amount of time people spend rearching, checking prices, visiting stores and eking advice from friends tends to ri in proportion to the value of the product they are thinking of buying. A new car is one of the biggest purchas people make, and buyers typically spend four to six weeks mulling over their choices. So why are some people now luby
walking into car showrooms and ordering a vehicle without even asking for a test drive? Or turning up at an electrical store and pointing out the washing machine they want without eking advice from a sales assistant? Welcome to a new style of shopping shaped by the internet.
B More people are buying products online, especially at peak buying periods. The total value of e-commerce transactions in the United States in the fourth quarter of 2004 reached $18 billon, a 22% increa over the same period in 2003, according to the Department of Commerce in Washington DC. But that just reprents 2% of America’s total retail market and excludes rvices, such as online travel, the value of goods auctioned on the Internet, and the $34 billion-worth of goods that individuals trade on eBay.
C If you consider the Internet’s wider influence over what people spend their money on, then the figures escalate out of sight. Some carmakers in America now find that eight out of ten of their buyers have logged on to the Internet to gather information about not just th
e exact vehicle they want, but also the price they are going to pay. Similarly with consumer electronics, nowadays if a customer wants to know which flat-screen TV they should buy, they are likely to start their shopping online – even though the vast majority will not complete the transaction there.
