题目内容
听力原文： Listen as a guide describes the ancient art of thatching a roof.
Welcome to the Four Winds Historical Farm, where traditions of the past are preserved for visitors like you. Today, our master thatchers will begin giving this barn behind me a sturdy thatched roof able to withstand heavy winds and last up to a hundred years. How do they do it？ Well, in a nutshell, thatching involves covering the beams or rafters--the wooden skeleton of a roof--with reeds or straw. Our thatchers here have harvested their own natural materials for the job--the bundles of water reeds you see lying over there beside the barn.
Thatching is certainly uncommon in the United States today. I guess that's why so many of you have come to see this demonstration. But it wasn't always that way. In the seventeenth century, the colonists here thatched their roofs with reeds and straw, just as they had done in England. After a while, though, they began to replace the thatch with wooden shingles because wood was so plentiful. And eventually, other roofing materials like stone, slate, and clay tiles came into use.
It's a real shame that most people today don't realize how strong and long-lasting a thatched roof is. In Ireland, where thatching is still practiced, the roofs can survive winds of up to one hundred ten miles per hour. That's because straw and reeds are so flexible. They bend but don't break in the wind like other materials can. Another advantage is that the roofs keep the house cool in the summer and warm in the winter. And then, of course, there's the roofs' longevity—the average is sixty years, but they can last up to a hundred. With all these reasons to start thatching roofs again, wouldn't it be wonderful to see this disappearing craft return to popularity？
26. What is about to be demonstrated？
27.What are thatched roofs made of？
28.According to the speaker, why did thatching die out in the United States？
29.According to the speaker, why does thatch survive strong winds？
30.According to the speaker, how might thatching become popular again？
(26)
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Section D
听力原文： Listen to a talk given by an astronaut.
Thank you. It's great to see so many of you interested in this series on "Survival in Outer Space". Please excuse the cameras--we're being videotaped for the local TV stations.
Tonight I'm going to talk about the most basic aspect of survival--the space suit. When most of you imagine an astronaut, that's probably the first thing that comes to mind, right？ Well, without space suits, it would not be possible for us to survive in space. For example, outer space is a vacuum--there's no gravity or air pressure; without protection, a body would explode. What's more, we'd cook in the sun or freeze in the shade---with temperatures ranging from a toasty 300 degrees above to a cool 300 degrees below zero Fahrenheit.
The space suit that NASA has developed is truly a marvel. This photo enlargement here is a life-size image of an actual space suit worn by astronauts on the last space shuttle mission. This part is the torso--it's made of seven extremely durable layers. This thick insulation protects against temperature extremes and radiation. Next is what they call a "bladder" of oxygen--that's an inflatable sac, filled with oxygen, to simulate atmospheric pressure. This bladder presses against the body with the same force as the Earth's atmosphere at sea level. The innermost layers provide liquid cooling and ventilation. Despite all the layers, the suit is flexible, allowing free movement so we Call work.
Another really sophisticated part of the space suit is the helmet. I brought one along to show you. Can I have a volunteer come and demonstrate？
21. What is the speaker's main purpose？
22.What would cause an unprotected human body to explode in outer space？
23.Where is the "bladder" of oxygen located？
24.What does the speaker show the audience as she describes the main part of the space suit？
25.What will probably happen next？
(21)
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