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单选题 北京观光客自然都会游览故宫和长城,这是因为故宫和长城是举世闻名的旅游景点。然而,对于北京第三大旅游场所——北京世界公园,人们却知之甚少。北京世界公园于20世纪90年代初竣工,占地面积46.7公顷,分为17处风景区,收集了各个洲的主要名胜景点。北京世界公园的规模雄踞亚洲同类公园之冠,所收微缩(miniature)复制品的数量也堪称亚洲之最。世界七大奇观以及50个国家的约100处历史名胜和自然景观均以微缩模型展出。
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单选题 He is usually well-behaved, this rudeness is only a(n) lapse.
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单选题I always have been ______ in self-confidence and decision.
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单选题None of you ______ to stay until the game is over, if you don't want to.
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单选题The evil manners would be ______ root and branch due to the forceful action taken by the local government.
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单选题The purpose of this passage is______.
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单选题
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单选题______ is believing.
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单选题Within the arid regions (in which) their culture developed, the Bedouin camel-breeding tribes have maintained a distinctive pattern and a dominant position (over) other societies and (settlements) (through) virtue of their ability to exploit brazing ranges.
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单选题
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单选题Gene therapy and gene-based drugs are two ways we could benefit from our growing mastery of genetic science. But there will be others as well. Here is one of the remarkable therapies on the cutting edge of genetic research that could make their way into mainstream medicine in the coming years. While it's true that just about every cell in the body has the instructions to make a complete human, most of those instructions are inactivated, and with good reason: the last thing you want for your brain cells is to start churning out stomach acid or your nose to turn into a kidney. The only time cells truly have the potential to turn into any and all body parts is very early in a pregnancy, when so-called stem cells haven't begun to specialize. Yet this untapped potential could be a terrific boon to medicine. Most diseases involve the death of healthy cells-brain cells in Alzheimer's, cardiac cells in heart disease, pancreatic cells in diabetes, to name a few. If doctors could isolate stem cells, then direct their growth, they might be able to furnish patients with healthy replacement tissue. It was incredibly difficult, but last fall scientists at the University of Wisconsin managed to isolate stem ceils and get them to grow into neural, gut, muscle and bone cells. The process still can't be controlled, and may have unforeseen limitations; but if efforts to understand and master stem-cell development prove successful, doctors will have a therapeutic tool of incredible power. The same applies to cloning, which is really just the other side of the coin; true cloning, as first shown with the sheep Dolly two years ago, involves taking a developed cell and reactivating the genome within, resetting its developmental instructions to a pristine state. Once that happens, the rejuvenated cell can develop into a full-fledged animal, genetically identical to its parent. For agriculture, in which purely physical characteristics like milk production in a cow or low fat in a hog have real market value, biological carbon copies could become routine within a few years. This past year scientists have done for mice and cows what Ian Wilmut did for Dolly, and other creatures are bound to join the cloned menagerie in the coming year. Human cloning, on the other hand, may be technically feasible but legally and emotionally more difficult. Still, one day it will happen. The ability to reset body cells to a pristine, undeveloped state could give doctors exactly the same advantages they would get from stem cells., the potential to make healthy body tissues of all sorts, and thus to cure disease. That could prove to be a true "miracle cure./
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单选题______ entered the classroom when he realized that he had forgotten his home-work.
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单选题Shortage of capital is the main factor that ______economic development.
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单选题 话题:要勇于面对挑战We should face challenges bravely Directions: For this part, you are allowed 30 minutes to write an essay on facing challenges by referring to the saying 'You cannot change what you refuse to confront.' You can give examples to illustrate your point and then explain how you will react to challenges in your life. You should write at least 150 words but no more than 200 words.
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单选题I'm going to ______ bank. I'm going to ______ Lloyd's Bank. A. the, the B. the, - C. -, the D.-,-
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单选题In Disneyland, every year, some 800, 000 plants are replaced because Disney refusedto______signs asking his "guests" not to step on them. A. put down B. put out C. put up D. put off
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单选题(2001) Only when they______the importance of the plan, will they make up their minds to carry it on.
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单选题History will always ______ any intended route and take an unforeseen one instead.
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单选题Building this road will ______ the construction of ten bridges, then the total cost reaches 1 million US Dollars. A. evolve B. involve C. revolve D. devolve
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单选题In the early 1960s Wilt Chamberlain was one of only three players in the National Basketball Association(NBA)listed at over seven feet. If he had played last season, however, he would have been one of 42. The bodies playing major professional sports have changed dramatically over the years, and managers have been more than willing to adjust team uniforms to fit the growing numbers of bigger, longer frames. The trend in sports, though, may be obscuring an unrecognized reality: Americans have generally stopped growing. Though typically about two inches taller now than 140 years ago, today"s people especially those born to families who have lived in the U.S. for many generations-apparently reached their limit in the early 1960s. And they aren"t likely to get any taller. "In the general population today, at this genetic, environmental level, we"ve pretty much gone as far as we can go," says anthropologist William Cameron Chumlea of Wright State University. In the case of NBA players, their increase in height appears to result from the increasingly common practice of recruiting players from all over the world. Growth, which rarely continues beyond the age of 20, demands calories and nutrients-notably, protein-to feed expanding tissues. At the start of the 20th century, under-nutrition and childhood infections got in the way. But as diet and health improved, children and adolescents have, on average, increased in height by about an inch and a half every 20 years, a pattern known as the secular trend in height. Yet according to the Centers for Disease Control and Prevention, average height-5"9" for men, 5"4" for women-hasn"t really changed since 1960. Genetically speaking, there are advantages to avoiding substantial height. During childbirth, larger babies have more difficulty passing through the birth canal. Moreover, even though humans have been upright for millions of years, our feet and back continue to struggle with bipedal posture and cannot easily withstand repeated strain imposed by oversize limbs. "There are some real constraints that are set by the genetic architecture of the individual organism," says anthropologist William Leonard of Northwestern University. Genetic maximums can change, but don"t expect this to happen soon. Claire C. Gordon, senior anthropologist at the Army Research Center in Natick, Mass., ensures that 90 percent of the uniforms and workstations fit recruits without alteration. She says that, unlike those for basketball, the length of military uniforms has not changed for some time. And if you need to predict human height in the near future to design a piece of equipment, Gordon says that by and large, "you could use today"s data and feel fairly confident."
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