Explorer of the Extreme Deep
Oceans cover more than two-thirds of our planet. Yet, just a small fraction of the underwater world has been explored. Now, Scientists at the Woods Hole Oceanographic Institution (WHOI) in Massachusetts are building an underwater vehicle that will carry explorers as deep as 6,500 meters (21,320 feet). The new machine, known as a manned submersible or human-operated vehicle (HOV), will replace another one named Alvin which has an amazing record of discovery, playing a key role in various important and famous undersea expeditions. Alvin has been operating for 40 years but can go down only 4,500 meters (14,784 feet). It's about time for an upgrade, WHOI researchers say.
Alvin was launched in 1964. Since then, Alvin has worked between 200 and 250 days a year, says Daniel Fornari, a marine geologist and director of the Deep Ocean Exploration Institute at WHOI. During its lifetime, Alvin has carried some 12,000 people on a total of more than 3,000 dives. A newer, better versions of Alvin is bound to reveal even more surprises about a world that is still full of mysteries, Fornari says. It might also make the job of exploration a little easier. "We take so much for granted on land," Fomari says. "We can walk around and see with our eyes how big things are. We can see colors, special arrangements."
Size-wise, the new HOV will be similar to Alvin. It'll be about 37 feet long. The setting area inside will be a small sphere, about 8 feet wide, like Alvin, it'll carry a pilot and two passengers. It will be just as maneuverable. In most other ways, it will give passengers more opportunities to enjoy the view, for one thing. Alvin has only three windows, the new vehicle will have five, with more overlap so that the passengers and the pilot can see the same thing.
Alvin can go up and down at a rate of 30 meters every second, and its maximum speed is 2 knots (about 2.3 miles per hour), while the new vehicle will be able to ascend and descend at 44 meters per second. It'll reach speeds of 3 knots, or 3.5 miles per hour.
What is Alvin?
A research institute.
B. A transporting vehicle.
C. A submersible.
D. A scientist.
听力原文: Mass media is the term used to denote, as a class, that section of the media specifically conceived and designed to reach a very large audience. It emerged in the 1920s with the advent of nationwide radio networks and of mass-circulation newspapers and magazines.
Media is a contraction of the term media of communication, referring to those organized means of dissemination of fact, opinion, and entertainment such as newspapers, magazines, cinema films, radio, television, and the World Wide Web.
During the 20th century, the advent of mass media was driven by technology that allowed the massive duplication of material at a low cost. Physical duplication technologies such as printing, record pressing and film duplication allowed the duplication of books, newspapers and movies at low prices to huge audiences. Television and radio allowed the electronic duplication of content for the first time.
In a democratic society, an independent media serves to educate the public about issues regarding government and corporate entities.
During the last decade of the 20th century, the advent of the World Wide Web marked the first era in which any individual could have a means of exposure on the scale of mass media.
(33)
A. Influence of mass media on our lives.
B. Profitability of mass media.
C. Mass media and its short history.
D. Mass media and politics.