单选题The recent medical breakthrough was the culmination of many long years of experimentation.

单选题By and by he discovered that the black night had changed to gray, bringing new hope to him.

单选题Ralph would not Uconcede/U that the work of the detectives was likely to be in vain given the price offered.

单选题Some measured all actions by the unalterable rule of right, and the Ueternal/U fitness of things.

单选题The engine was ______ by a tree lying across the line.

单选题Speaker A: The train is delayed again. Speaker B: ______ How long do we have to wait? Speaker A: About forty minutes.

单选题A: It's too cold. Are you near the door? B: ______.

单选题{{B}}Passage Two{{/B}} If two scientists at Los Alamos National Laboratory are correct, People will still be driving gasoline-powered cars 50 years from now, giving out heat-trapping carbon dioxide into the atmosphere--and yet that carbon dioxide will not contribute to global warming. The scientists, F. Jeffrey Martin and William L. Kubic Jr., are proposing a concept, which they have patriotically named Green Freedom for removing carbon dioxide from the air and turning it back into gasoline. The idea is simple. Air would be blown over a liquid solution which would absorb the carbon dioxide. The carbon dioxide would then be extracted and subjected to chemical reactions that would turn it into fuel. Although they have not yet built a fuel factory, or even a small prototype, the scientists say it is all based on existing technology. "Everything in the concept has been built, is operating or has a close cousin that is operating," Dr. Martin said. The proposal does not violate any laws of physics, and other scientists have independently suggested similar ideas. In the efforts to reduce humanity's emissions of carbon dioxide, three solutions have been offered; hydrogen-powered cars, electric cars and biofuels. Biofuels are gasoline substitutes produced from plants like corn or sugar cane. Plants absorb carbon dioxide as they grow, but growing crops for fuel takes up wide strips of land. Hydrogen-powered cars emit no carbon dioxide, but producing hydrogen requires energy, and if that energy comes from coal-fired power plants, then the problem has not been solved. The problem with electric cars is that they have typically been limited to a range of tens of miles as opposed to the hundreds of miles that can be driven on a tank of gas. Gasoline, it turns out, is an almost ideal fuel (except that it produces carbon dioxide). If it can be made out of carbon dioxide in the air, the Los Alamos concept may mean there is little reason to switch, after all. "It's definitely worth pursuing," said Martin I. Hoffert, a professor of physics at New York University. "It has a couple of pieces to it that are interesting." Other scientists also said the proposal looked promising but could not evaluate it fully because the details had not been published.

单选题A: Reservations. How may I help you? B: ______.

单选题{{B}}Passage Three{{/B}} After watching my mother deal with our family of five, I can't understand why her answer to the question, "What do you do?" is always, "Oh, I'm just a housewife." JUST a housewife? Anyone who spends most of her time in meal preparation and cleanup, washing and drying clothes, keeping the house clean, leading a scout troop, playing taxi driver to us kids when it's time for school, music lessons or the dentist, doing volunteer work for her favorite charity, and making sure that all our family needs are met is not JUST a housewife. She's the real Wonder Woman. Why is it that so many mothers like mine think of themselves as second-class or something similar? Where has this notion come from? Have we males made them feel this way? Has our society made "going to work" outside the home seem more important than what a housewife must face each day? I would be very curious to see what would happen if a housewife went on strike. Dishes would pile up. Food in the house would run out. No meals would appear on the table. There would be no clean clothes when needed. High boots would be required just to make it through the house scattered with garbage. Walking and bus riding would increase. Those scout troops would have to break up. Charities would suffer. I doubt if the man of the house would be able to take over. Oh, he might start out with the attitude that he can do just as good a job, but how long would that last? Not long, once he had to come home each night after work to more household duties. There would be no more coming home to a prepared meal; he'd have to fix it himself. The kids would all be screaming for something to eat, clean clothes and more bus fare money. Once he quieted the kids, he'd have to clean the house, go shopping, make sure that kids got a bath, and fix lunches for the next day. Once the kids were down for the night, he might be able to crawl into an unmade bed and try to read the morning newspaper. No, I don't think many males are going to volunteer for the job. I know I don't want it. So, thanks, mom! I'll do what I can to create a national holiday for housewives. It could be appropriately called Wonder Woman Day.

单选题Man: It seems to me that you're getting on well with your neighbors.Woman: We really hit it off. Our neighbors are incredibly outgoing and hospitable.Question: What do we learn about the relationship between the woman and her neighbors?

单选题Had it not been for your timely help, our company would have been on the verge of ______.

单选题Watching me pulling the calf awkwardly to the barn, the Irish milkmaid fought hard to Uhold back/U her laughter.

单选题He merely meant to give his opinion, not to start an argument.

单选题It was an allusion to what the scientist thought was an inappropriate distribution o funds for stem cell research.

单选题The Constitution stipulates that every citizen has the sacred obligation to defend his country.

单选题If those "mad moments"--when you can't remember what your friend has told you or where you left your keys--are becoming more frequent, mental exercises and a healthy brain diet may help. Just as bodies require more maintenance with the passing years, so do brains, which scientists now know show signs of aging as early as the 20s and 30s. "Brain aging starts at a very young age, younger than any of us had imagined and these processes continue gradually over the years," said Dr. Gary Small, the director of the Center on Aging at the University of California, Los Angeles. 'Tin convinced that it is never too early to get started on a mental or brain-fitness program," he added. In his book, The Memory Bible, the 51-year-old neuroscientist (神经学家) lists what he refers to as the 10 suggestions for keeping the brain young. They include training memory, building skills, reducing stress, mental exercises, brain food and a healthy lifestyle. "Misplacing your keys a couple of times don't mean you should start labeling your cabinets. Memory loss is not an inevitable consequence of aging. Our brains can fight back," he said. Small provides the weapons for a full-scale attack. Simple memory tests give an indication of what you are up against and tools such as "look" and "connect" are designed to make sure that important things such as names and dates are never forgotten. "So if you wanted to learn names and faces, for example, you meet Mrs. Beatty and you notice a distinguishing facial feature, maybe a high eyebrow," said Small. "You associate the first thing that comes to your mind. I think of the actor Warren Beatty, so I create a mental picture of Warren Beatty kissing her brow." Small admits it may sound a bit strange but he says it works. "Mental exercises could be anything from doing crossword puzzles and writing with your left hand if you are right handed or learning a language. It could be anything that is fun that people enjoy doing," he added.

单选题The author quotes the example of our ancestors to show that education emerged ______

单选题Difficulties and hardships have ______ the best qualities of the young geologist.