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What are the chances that we will encounter some alien form of life, as we explore the galaxy.If the argument about the time scale for the appearance of life on Earth is correct, there ought to be many other stars, whose planets have life on them. Some of these stellar systems could have formed 5 billion years before the Earth. So why is the galaxy not crawling with self designing mechanical or biological life forms Why hasn’t the Earth been visied, and even colonized. I discount suggestions that UFOs contain beings from outer space. I think any visits by aliens would be much more obvious, and probably also, much more unpleasant.What is the explanation of why we have not been visitedOne possibility is that the argument about the appearance of life on Earth is wrong. Maybe the probability of life spontaneously appearing is so low that Earth is the only planet in the galaxy, or in the observable universe, in which it happened.Another possibility is that there was a reasonable probability of forming self-reproducing system, like cells, but most of these forms of life did not evolve intelligence.A third possibility is that there is a reasonable probability for life to form, and to evolve to intelligent beings, in the external transmission phase. But at that point, the system becomes unstable, and the intelligent life destroys itself. This would be a very pessimistic conclusion. I very much hope it isn’t true.I prefer a fourth possibility: there are other forms of intelligent life out there, but we have been overlooked. There used to be a project called SETI, the search for extraterrestrial intelligence. It involved scanning the radio frequencies, to see if we could pick up signals from alien civilizations. I thought this project was worth supporting, though it was cancelled due to a lack of funds. But we should have been wary of answering back, until we have developed a bit further. Meeting a more advanced civilization, at our present stage, might be a bit like the original inhabitants of America meeting Columbus. I don’t think they were better off for it. What does the word "discount" (Line 6, Para. 1) most probably mean according to the context （）
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D The first Olympic Games were held in 776 BC. They began as a religious festival and were held every four years. They were held in a valley of Ancient Greece called Olympia. Athletes came to Olympia to train full time for ten months prior to the Olympics. They had to undergo an examination of a ten-member panel who assessed them on their character and physical ability. Women were not allowed to participate in these early Olympic games and could not attend tile games. At the first games in 776 BC, the only event held was a foot race and was the length of the stadium. Later, a chariot race was added and was one of the most exciting events of these Olympics. The race was nine miles long. The prize for the victors of these early Olympics was a simple olive tree branch. Today, the Olympics are one of the most exciting events televised. People from all over the world watch to see the athletes from their countries compete in over twenty-eight events. According to the text, the Olympic Games today probably has ______.
EHoliday Inn Select (716) 291—2837300 Third Street Discover the rich history of Western NYNiagara Falls, NY 14303(716) 285—3361 Aquarium of NiagaraAdvance booking is required. 701 Whirlpool St. Luna; NY 14301Rizzo’s Used Furniture and Antiques Dive into a world of discovery with over 15001601 18th Street kinds of water life like sharks, sea horses, eels,Ramada, NY 14025 etc.(716) 284—1931 Open year round from 9 am on weekends. Mondays and Wednesdays in summer. Parking isDaredevil Museum free!423 Rainbow Boulevard S. (716) 290-3847Terrapin, NY 14290 Where can you probably read this list
阅读下面短文，从短文后所给各题的四个选项([A]、[B]、[C]和[D])中选出能填入相应空白处的最佳选项。 Some students at the Open University left school 20 years ago. (36) are younger but all must be at least 21 years old. This is one example of (37) the Open University is different (38) all the others. Its students must (39) work fulltime or be at home all day. They do not have to (40) any examinations before they are (41) . This is why the university is called "open". It was started (42) order to help people who (43) having a university education when they were young. The first name (44) the open university was "the University of the Air". The idea was to teach (45) the air, in other (46) , on radios and the television. (47) of the teaching is done like this. The student also receives (48) at one of 283 study centers in the country. He must also (49) three weeks every summer as a (50) student. Tutors and students (51) and study together, (52) in other universities. At the end of the Open University’s first year, the (53) were good; three (54) of four students passed their examinations. (55) they do this every year, they will finish their studies in four or five years.
EHoliday Inn Select (716) 291—2837300 Third Street Discover the rich history of Western NYNiagara Falls, NY 14303(716) 285—3361 Aquarium of NiagaraAdvance booking is required. 701 Whirlpool St. Luna; NY 14301Rizzo’s Used Furniture and Antiques Dive into a world of discovery with over 15001601 18th Street kinds of water life like sharks, sea horses, eels,Ramada, NY 14025 etc.(716) 284—1931 Open year round from 9 am on weekends. Mondays and Wednesdays in summer. Parking isDaredevil Museum free!423 Rainbow Boulevard S. (716) 290-3847Terrapin, NY 14290 To buy an old-fashioned table, one should go to ______.
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