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1、a chance to make a trip into space with my friend Li Yanping, an astronomer. We visited the moon in our spaceship!Before we leave, Li Yanping explained to me that the forece of the gravity would change three times on our journey and that the first change would be the most powerful. Then we were off.
2、 As the rocket rose into the air, we were pushed back into our seats because we were trying to escape the pull of the earths gravity. It was so hard that we could not say anything to each other. Gradually the weight lessened and I was able to talk to him. “ Why is the spaceship not falling back to t
3、he earth? On the earth if I fall from a tree I will fall to ground.” I asked. “ We are too far from the earth now to feel its pull, “ he explained, “ so we feel as if there is no gravity at all. When we get closer to the moon, we shall feel its gravity pulling us, but it will not be as strong a pull
4、 as the earths. “ I cheered up immediately and floated weightlessly around in our spaceship cabin watching the earth become smaller and the moon larger.When we got there, I wanted to explore immediately. “ Come on,” I said. “ If you are right, my mass will be less than on the earth because the moon
5、is smaller and I will be able to move more freely. I might even grow taller if I stay here long enough. I shall certainly weigh less!” I laughed and climbed down the steps from the spaceship. But when I tried to step forward, I found I was carried twice as far as on the earth and fell over. “ Oh dea
6、r,” I cried, “ walking does need a bit of practice now that gravity has changed.” After a while I got the hang of it and we began to enjoy ourselves.Leaving the moons gravity was not as painful as leaving the earths. But returning to the earth was very frightening. We watched, amazed as fire broke o
7、ut on the outside of the spaceship as the earths gravity increased. Again we were pushed back hard into our seats as we came back to land. “ That was very exhausting but very exciting too,” I said. “Now I know much more about gravity! Do you think we could bisit some stars next time?” “Of course,” h
8、e smiled, “ which star would you like to go to?”Caught by a black holeThe spaceship warned Li Yanping and me to be ready as we were approaching the “black hole”. We could see some faint lights around what looked like an empty space. Li Yanping said, “ That empty hole is like a mouth always needing t
9、o be fed. Those lights are thins that are being pulled into time by the gravity of the hole.” We watched with interest and amazement at the lights which seemed to be going fainter and fainter round the edge of the black hole. Just then the lights on our spaceship went our the and the computer stoppe
10、d working. What was happening? I tried to turn the spaceship away from the hole but it would not move. Would it eat us too?Suddenly the spaceship jumped and began to move round the edge of trhe hole too. The gravity of the “black hole” was pulling us into its “mouth”. As the spaceship moved round th
11、e black hole, I felt rather sick. My mouth went dry and I closed my eyes. All the stories about what happened when you were caught by the gravity of a “black hole” seem to be true.But then the spaceship jumped again. This time it moved sideways and away from this edge of the “black hole”. Someone wa
12、tching me would have seen the spaceship flying like a bird away from the “black hole”. But we felt nothing. At last we were able to look around us. Luckily the computer had started working again. We realized that we had discovered something new about “black hole”. If you go inside the edge of a “bla
13、ck hole”, it will “eat” you and there is no escape; but if you do not, you may have an opportunity to escape. How exciting!Unit 5A trip on “ The True North”Li Daiyu and her cousin Liu Qian were on a trip to Canada to bisit their cousins in Montreal on the Atlantic coast. Rather than take the aeropla
14、ne all the way, they decided to fly to Vancouver and then take the train west to east across Canada. The though that they could cross the whole continent was exciting.Their friend, Danny Lin, was waiting at the airport. He was going to take them and their baggage to catch “The True North”, the cross
15、 Canada train. On the way to the statiion, he chatted about their trip. “Youre going to see some great scenery. Going eastward, youll pass mountains and thousands of lakes and forests, as well as wide rivers and large cities. Some people have the idea that you can cross Canda in less than fice days,
16、 but they forget the fact that Canada is 5500 kilometers from coast to coast. Here in Vancouver, youre in Canadas warmest part. People say it is Canadas most beautiful city, surrounded by mountains and the Pacific Ocean. Skiing in the Rocky Mountains and sailing in the harbour make Vancouver one of
17、Canadas most popular cities to live in. Its population is increasing rapidly. The coast north of Vancouver has some of the oldest and most beautiful forests in the world. It is so wet there that the trees are extremely tall, some measuring over 90 metres.”That afternoon aboard the train, the cousins
18、 settled down in their seats. Earlier that day, when they crossed the Rocky Mountains, they managed to catch sight of some mountain goats and even a grizzly bear and an eagle. Their next stop was Calgary, which is famous for the Calgary Stampede. Cowboys from all over the world come to compete in th
19、e Stampede. Many of them have a gift for riding wild horses and can win thousands of dollars in prizes.After two days travel, the girls began to realize that Canada is quite empty. At school, they had learned that most Canadians live within a few hundred kilometres of the USA border, and Canadas pop
20、ulation is only slightly over thirty million, but now they were amazed to see such an empty country. They went through a wheat-growing province and saw farms that covered thousands of acres. Afrer dinner, they were back in an urban area, the busy port city of Thunder Bay at the top of the Great Lake
21、s. Because of the Great Lakes, they learned, Canada has more fresh water than any other country in the world. In fact, it has one-third of the worlds total fresh water, and much of it is in the Great Lakes.That night as they slept, the train rushed across the top of Lake Superior, through the great
22、forests and southward towads Toronto.“The True North” from Toronto to MontrealThe next morning the bushes and maple trees outside their window were red, gold and orange, and there was frost on the ground, confirming that fall had arrived in Canada.Around noon they arrived in Toronto, the biggest and
23、 most wealthy city in Canada. They were not leaving for Montreal until later, so they went on a tour of the city. They went up the tall CN Tower and looked across the lake. In the distance, they could see the Misty cloud that rose from the great Niagara Falls, which is on the south side of the lake.
24、 The water flows into the Niagara River and over the falls on its way to the sea.They saw the covered stadium, home of several famous basketball teams. As they walked north from the harbour area, Li Daiyu said, “Lin Fang, one of my mothers old schoolmates, lives here. I should phone her from a telep
25、hone booth.”They met Lin Fei around dusk in downtown Chinatown, one of the three in Toronto. Over dinner at a restaurant called The Pink Pearl, the cousins chatted with Lin Fei, who had moved to Canada many years earlier. “We can get good Cantonese food here,” Lin Feitold them, “ because most of the
26、 Chinese people here come from South China, especially Hong Kong. Its too bad you cant go as far as Ottawa, Canadas capital. Its approximately four hundred kilometers northeast of Toronto, so it would take too long.”The train left late that night and arrived in Montreal at dawn the next morning. At
27、the station, people everywhere were speaking French. There were sighs and ads in French, but some of them had English words in smaller letters. “We dont leave until this evening,” said Liu Qian. “Lets go downtown. Old Montreal is close to the water.” They spent the afternoon in lovely shops and visi
28、ting artists in their workplaces beside the water. As they sat in a Buffet restaurant looking over the broad St Lawrence River, a young man sat down with them.“Hello, my name is Henri. Im a student at the university nearby,” he said,” and I was wondering where you are from.” The girls told him they
29、were on a trp across Canada and that they had only on day in Montreal. “Thats too bad,” he said. “Montreal is a city with wonderful restaurants and clubs. Most of us speak both English and French, but the city has French culture and traditions. We love good coffee, good bread and good music.”That ni
30、ght as the transfer was speeding along the St Lawrence River toward the Gulf of St Lawrence and down to the distant east coast, the cousins dreamed of French restaurants and red maple leaves.Iqaluit the frozen townThe reporter, Beth Allen, arrived in a northern community called Iqaluit in Nunavut. N
31、unavut was created in 1999 as a special area for Inuit people. Its name means “Our Land” in their language. It is in the farthest northeastern area of Canada, north or the Arctic Circle, and is very cold the average witer temperature in Nunavut is 35 degrees below zero.Beth said, “ I knew it would b
32、e could in January, but not this cold! Maybe there is a dog sled that can take me into town.”The quiet man who had been on the plane with her said, “Ill take you into town, but I dont hace a dog sled. Most people only use the dogs for competitions, why are you visiting Iqaluit?”Beth answered, “ Im w
33、riting a story for my newspaper about Iqaluit wed like to advertise it as a holiday place, but I think its too cold.”The man laughed. “My name is Simon and I am Inuit,” he said. “I think its too far north here for holidays but more and more tourists are coming. They like ice fishing and photographin
34、g polar bears. I star as far away from polar bears as possible. I like my warm office and my warm house.”“Im business man. My grandfather would live in ice houses when he hunted in winter, but not so many people do that now. the old men used to make one in a few hours. They used to live in skin tent
35、s in summer the tents were easy to move so the people could follow the animals.”A few minutes later they arrived in Iqaluit, a town with a population of 6000, on Simons snowmobile. It was two oclock in the afternoon, but it was already dark, and all the houses shone with bright lights. Beth said, “
36、Why is it so dark? Its the middle of the day!”Simon replied, “Its dark in the day because we are so far north. You should come in June. The sun shines all night in the north then. Thats why its called The Land of the Midnight Sun.” There were people on the streets and snowmobiles everywhere. There w
37、ere even a few dog teams.必修四Unit 1A STUDENT OF AFRICAN WILDLIFEIt is 5:45 am and the sun is just rising over Gombe National park in east Africa.Following Janes way of studying chimps,our group are all going to visit them in the forest.Jane has studied these families of chimps for many years and help
38、ed people understand how much they behave like humans. Watching a familyof chimps waking up is our first activity of the day. This means going back to the place where we left the family sleeping in a tree the night before.Everybody sits and waits in the shade of the trees while the family begins to
39、wake up and move off.Then we follow as they wonder into the forest.Most of the time,chimps either feed or clean each other as a way of showing love in their family.Jane worns us that our grou is going tobe very tired and dirty生态型原种种猪扩繁工程 可行性报告patience and understanding and for the kindly encourageme
40、nt he gave us when we went so unwillingly to school. A great many former pupils will be attending a farewell dinner in his honour next Thursday. It is a curious coincidence that the day before his retirement, Mr Page will have been teaching for a total of forty years. After he has retired, he will d
41、evote himself to gardening. For him, this will be an entirely new hobby. But this does not matter, for, as he has often remarked, one is never too old to learn. Lesson86 Out of control 失控As the man tried to swing the speed-boat round, the steering-wheel came away in his hands. He waved desperately t
42、o his companion, who had been water-skiing for the last fifteen minutes. Both men had hardly had time to realize what was happening when they were thrown violent1y into the sea. The speed-boat had struck a buoy, but it continued to move very quickly across the water. Both men had just begun to swim
43、towards the shore. when they noticed with dismay that the speed-boat was moving in a circle. It now came straight towards them at tremendous speed. In less than a minute, it roared past them only a few feet away. After it had passed, they swam on as quickly as they could because they knew that the b
44、oat would soon return. They had just had enough time to swim out of danger when the boat again completed a circle. On this occasion, however, it had slowed down considerably. The petrol had nearly all been used up. Before long, the noise dropped completely and the boat began to drift gently across t
45、he water.Lesson87 A perfect alibi 极好的不在犯罪现场的证据At the time the murder was committed, I was travelling on the 8.0 oclock train to London, said the man.Do you always catch such an early train ? asked the inspector.Of course I do, answered the man. I must be at work at 10.0 oclock. My employer will conf
46、irm that I was there on time. Would a later train get you to work on time ? asked the inspector. I suppose it would, but I never catch a later train.At what time did you arrive at the station ?At ten to eight. I bought a paper and waited for the train.And you didnt notice anything unusual ? Of cours
47、e not.I suggest, said the inspector, that you are not telling the truth. I suggest that you did not catch the 8.0 oclock train, but that you caught the 8.25 which would still get you to work on time. You see, on the morning of the murder, the 8.0 oclock train did not run at all. It broke down at Fer
48、ngreen station and was taken off the line.Lesson88 Trapped in a mine 困在矿井里Six men have been trapped in a mine for seventeen hours. If they are not brought to the surface soon they may lose their lives. However, rescue operations are proving difficult. If explosives are used, vibrations will cause th
49、e roof of the mine to collapse. Rescue workers are therefore drilling a hole on the north side of the mine. They intend to bring the men up in a special capsule. If there had not been a hard layer of rock beneath the soil, they would have completed the job in a few hours. As it is, they have been drilling for sixteen hours and they still have a long way to go. Meanwhile, a microphone, which was lowered into the mine t