1) 他们打算做的事已经做成了. (set out)
2) 他们的父亲希望他们早点儿回家. (prefer sb to do)
3) 他就其年龄而言, 身体极好.(in excellent condition)
4) 你知道人们对这种行为是怎样看待的吗?(be conscious of)
5) 我坚决要求你立刻采取行动把事情处理好. (insist on)
We can read of things that happened 5,000 years ago in the Near East, where people first learned to write. But there are some parts of the word where even now people cannot write. The only way that they can preserve their history is to recount it as sagas -- legends handed down from one generation to another. These legends are useful because they can tell us something about migrations of people who lived long ago, but none could write down what they did. Anthropologists wondered where the remote ancestors of the Polynesian people, who now living in the Pacific Islands, came from. The sagas of these people explain that some of them came from Indonesia about 2,000 years ago.
But the first people who were like ourselves lived so long ago that even their sagas, if they had any, are forgotten. So archaeologists have neither history nor legends to help them to find out where the first 'modern men' came from.
Fortunately, however, ancient men made tools of stone, especially flint, because this is easier to shape than other kinds. They may also have used wood and skins, but these have rotted away. Stone does not decay, and so the tools long ago have remained when even the bones of the men who made them have disappeared without trace.
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 Clemmonss 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 4.5-metre 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 33.5-tonne column. Even a modest force, if sustained over a long time, would do. The key was to use a pulley system that would magnify the applied force. So they rigged up a tent-shaped scaffold directly above the tip of the horizontal column, with pulleys suspended from the scaffolds apex. The idea was that as one end of the column rose, the base would roll across the ground on a trolley. Earlier this year, the team put Clemmonss unlikely theory to the test, using a 40-square-metre rectangular nylon sail. The kite lifted the column clean off the ground. We were absolutely stunned, Gharib says. The instant the sail opened into the wind, a huge force was generated and the column was raised to the vertical in a mere 40 seconds.
The wind was blowing at a gentle 16 to 20 kilometres an hour, little more than half what they thought would be needed.
What they had failed to reckon with was what happened when the kite was opened. There was a huge initial force- five times larger than the steady state force, Gharib says.
This jerk meant that kites could lift huge weights, Gharib realised. Even a 300-tonne column could have been lifted to the vertical with 40 or so men and four or five sails.
So Clemmons was right: the pyramid builders could have used kites to lift massive stones into place. Whether they actually did is another matter, Gharib says.
There are no pictures showing the construction of the pyramids, so there is no way to tell what really happened.
The evidence for using kites to move large stones is no better or worse than the evidence for the brute force method, Gharib says.
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
1 .It is generally believed that large numbers of people were needed to build the pyramids.
2 .Clemmons found a strange hieroglyph on the wall of an Egyptian monument.
3. Gharib had previously done experiments on bird flight. 4. Gharib and Graff tested their theory before applying it.
5 .The success of the actual experiment was due to the high speed of the wind.
6 .They found that, as the kite flew higher, the wind force got stronger.
7 .The team decided that it was possible to use kites to raise very heavy stones.