tailieunhanh - IELTS Academic Reading Sample 158 - Pulling string to build pyramids

Hi vọng IELTS Academic Reading Sample 158 - Pulling string to build pyramids sẽ cung cấp những kiến thức bổ ích cho các bạn trong quá trình ôn tập nâng cao kiến thức trước khi bước vào kì thi của mình. Mời các bạn cùng tham khảo. | You should spend about 20 minutes on Questions 1-13 which are based on Reading Passage 158 below. Pulling string to build pyramids No one knows exactly how- the pyramids were built. Marcus Chown reckons the answer could be hanging in the air The pyramids of Egypt were built more than three thousand years ago and no one knows how. The conventional picture is that tens .of thousands of slaves dragged stones on sledges. But there is no evidence to back this up. Now a Californian software consultant called Maureen Clemmons has suggested that kites might have been- involved. While perusing a book on the monuments of Egypt she noticed a hieroglyph that showed a row of men standing in odd postures. They were holding what looked like ropes that led via some kind of mechanical system to a giant bird in the sky. She wondered if perhaps the bird was actually a giant kite and the men were using it to lift a heavy object. Intrigued Clemmons contacted Morteza Gharib aeronautics professor at the California Institute of Technology. He was fascinated by the idea. Coming from Iran I have a keen interest in Middle Eastern science he says. He too was puzzled by the picture that had sparked Clemmons s interest. The object in the sky apparently had wings far too short and wide for a bird The possibility certainly existed that it was a kite he says. And since he needed a summer project for his student Emilio Graff investigating the possibility of using kites as heavy lifters seemed like a good idea. Gharib and Graff set themselves the task of raising a stone column from horizontal to vertical using no source of energy except the wind. Their initial calculations and scale- model wind-tunnel experiments convinced them they wouldn t need a strong wind to lift the column. Even a modest force if sustained over a long lime rose the base would 4 roll across the ground on a trolley. Earlier this year the team put Clemmons s unlikely theory to the test using a 40-square- .

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