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In September, in Britain, you may see a lot of birds (36) on roofs and telegraph wires. These birds are swallows. They are (37) together because, very soon, they will be flying (38) to much warmer lands, where they will find (39) small flying insects on which they (40) . There are no such insects (41) in Britain during the winter, as it is (42) cold for them. The swallows settle, fly off, swoop, and (43) again. This they do many times, for they are making short (44) flights in order to be fit for the long journey (45) them. (46) of these migrating birds leave Britain in the autumn. They fly (47) for hundreds of miles (48) they reach the warm lands of Africa. But not all the birds get there, for many of them perish in the stormy weather they meet with (49) . In the spring of the following year they (50) the long and tiring journey back to Britain. They return to the identical barn or tree in the (51) district which they had left the (52) autumn. How do these birds find their (53) there and back over such vast distances Nobody knows exactly (54) , but it has something to do (55) winds and air currents.
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Your mother will only feel close to you if you respect her opinion and agree with her.
Every year landslides (滑坡) cause 25 to 50 deaths and $1.5 billion in damage in the United States. They account for 15 percent of the deaths from natural disasters in Europe. And in December, a single event killed more than 200 people in the Philippines. Sending workers to stabilize mountainsides using steel bars and cement (水泥) can help prevent disaster, but it introduces new difficulties. Shaking drills produce harmful dust and loosen heavy, dangerous debris (岩屑). "It’s quite a risky job, "says Giorgio Pezzuto of D’Appolonia, an engineering company in Italy. D’Appolonia, working with eight other companies, may have an answer: a three-ton robot called Roboclimber. "The idea is to operate a machine far away that can drill without a human being on board," says Pezzuto, the manager for the project, which is supported by the European Commission. Engineers claim that the machine will be faster and cheaper than manual labor. The robot, a large radio-controlled four-legged mechanical spider, has cost at least $2 million so far. The final product should be able to climb unstable mountainsides, drill holes, insert bars and cement, and collect data on the stability. Testing should begin in May. The biggest advantage of this product is that______.
We found that bar at last. I didn’t have to ask again, for there it was in big red neon letters over the window--Star Bar. There were some iron tables outside with plastic chairs around them. A few people sat around, looking at a portable television set that someone had brought out of the bar. They were all in thin summer dresses or short shirts; even at that late hour it was stifling. Two thin dogs lay under one of the tables with their tongues out, and some of the women were fanning them-selves unenthusiastically (无精打采地) with magazines. "He’s not here," I said, after a quick look around. The television was speaking out an advertisement for a detergent (洗衣粉) , and the people sitting round had their eyes glued to the picture of a woman proudly showing how white her husband’s underwear was after having been washed. They took no notice of us at ail. "Well, what did you expect" replied Fergus, yawning (打呵欠)." It’s only half past nine; and he said he would be here at nine. You ought to know Graig by this time. He’ll turn up sometime after ten.\ What does the underlined word "stifling" (Paragraph 1) probably mean
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