单选题Since the first brain scanner was constructed several years ago, computed tomography or computed medical imagery, has become fairly widely used. Its rapid acceptance is due to the fact that it has overcome several of the drawbacks of conventional X-ray technology. To begin with, conventional two-dimensional X-ray pictures cannot show all of the information contained in a three-dimensional object. Things at different depths are super imposed, causing confusion to the viewer. Computed tomography can give three-dimensional information. The computer is able to reconstruct pictures of the body"s interior by measuring the varying intensities of X-ray beams passing through sections of the body from hundreds of different angles. Such pictures are based on series of thin "slices". In addition, conventional X-ray generally differentiates only between bone and air, as in the chest and lungs. They cannot distinguish soft tissues or variations in tissues. The liver and pancreas are not discernible at all, and certain other organs max only be rendered visible through the use of radio paque dye. Since computed tomography is much more sensitive, the soft tissues of the kidneys or the liver can be seen and clearly differentiated. This technique can also accurately measure different degrees of X-ray absorption, facilitating the study of the nature of tissue. A third problem with conventional X-my methods is their inability to measure quantitatively the separate densities of the individual substances through which the X-ray has passed. Only the mean absorption of all the tissues is recorded. This is not a problem with computed tomography. It can accurately locate a tumor and subsequently monitor the progress of radiation treatment, so that in addition to its diagnostic capabilities, it can play a significant role in therapy.

单选题The team should play very hard because the championship of the state was______.

单选题Which of the information is true according to the passage?

单选题 National Geographic{{U}} (61) {{/U}}fill a number of roles, says Karen Kasmauski. "We are journalists; researcher, thinkers," she says, "photography is our{{U}} (62) {{/U}}." As one of the Society's six contributing photographers-in-residence, Karen seeks to focus{{U}} (63) {{/U}}attention on global changes and how they{{U}} (64) {{/U}}human health. One promising{{U}} (65) {{/U}}is the anti-measles{{U}} (66) {{/U}}in Kenya led by the American Red Cross, the Centers for Disease Control and Prevention, and UN{{U}} (67) {{/U}}. "These photographers-in-residence have chosen subjects they've been{{U}} (68) {{/U}}for years, subjects they're{{U}} (67) {{/U}}about," says program manager Charlene Valeri. Frans Lanting investigates{{U}} (70) {{/U}}and the danger of{{U}} (71) {{/U}}loss to animals in the wild. David Coubilet works to promote the survival of coral reef{{U}} (72) {{/U}}in the South Pacific. Sam Abell{{U}} (73) {{/U}}North American rivers from a cultural, historical, and ecological{{U}} (74) {{/U}}. Underwater photographer Emory Kristof will use{{U}} (75) {{/U}}-operated vehicles to take inventory of deep ocean{{U}} (76) {{/U}}in water off Indonesia. Annie Griffiths Belt is promoting{{U}} (77) {{/U}}of wilderness areas in North America, both in and outside of classrooms. By speaking to{{U}} (78) {{/U}}and displaying their work widely, the photographers hope to{{U}} (79) {{/U}}public support for the Society's{{U}} (80) {{/U}}.

单选题Like other religious groups, the Christian church's strong emphasis on holiness is essential to salvation. A. deemed B. doomed C. destined D. depicted

单选题It is unfortunate that the members of the committee do not______ in opinion. (2008年四川大学考博试题)

单选题Each passage is followed by some question or unfinished statements. For each of them there are four choices marked A, B, C, D. You should decide on the best choice and mark your answer on the ANSWER SHEET by blackening the corresponding letter in the brackets. Before high school teacher Kimberly Rugh got down to business at the start of a recent school week, she joked with her students about how she'd had to clean cake out of the comers of her house after her 2-year-old son's birthday party. This friendly combination of chitchat took place not in front of a blackboard but in an Email message that Rugh sent to the 135 students she's teaching at the Florida Virtual School, one of the nation's leading online high schools. The school's motto is "any time, any place, any path, any pace". Florida's E-school attracts many students who need flexible scheduling, from young tennis stars and young musicians to brothers Tobias and Tyler Heeb, who take turns working on the computer while helping out with their family's clam-farming business on Pine Island, off Florida's southwest coast. Home-schoolers also are well represented. Most students live in Florida, but 55 hail from West Virginia, where a severe teacher shortage makes it hard for many students to take advanced classes. Seven kids from Texas and four from Shanghai round out the student body. The great majority of Florida Virtual Schoolers--80 percent are enrolled in regular Florida public or private high schools. Some are busy overachievers. Others are retaking classes they barely passed the first time. The school's biggest challenge is making sure that students aren't left to sink or swim on their own. After the school experienced a disappointing course completion rate of just 40 percent in its early years, Executive Director Julie Young made a priority out of what she calls "relationship-building", asking teachers to stay in frequent E-mail and phone contact with their students. That personal touch has helped: The completion rate is now 80 percent. Critics of online classes say that while they may have a limited place, they are a poor substitute for the face-to-face contact and socialization that take place in brick-and-mortar classrooms. Despite opportunities for online chats, some virtual students say they'd prefer to have more interaction with their peers. Students and parents are quick to acknowledge that virtual schooling isn't for everyone. "If your child's not focused and motivated, I can only imagine it would be a nightmare," says Patricia Haygood of Orlando, whose two daughters are thriving at the Florida school. For those who have what it takes, however, virtual learning fills an important niche. "I can work at my own pace, on my own time," says Hackney. "It's the ultimate in student responsibility."

单选题Publication of this survey had originally been intended to coincide with the annual meetings of the World Bank and the International Monetary Fund, scheduled for September 29th—30th in Washington, D. C. Those meetings, and the big anti-globalization protests that had been planned to accompany them, were among the least significant casualties of the terrorist atrocities of September 11th. You might have thought that the anti-capitalist protesters, after contemplating those horrors and their aftermath, would be regretting more than just the loss of a venue for their marches. Many are, no doubt. But judging by the response of some of their leaders and many of the activists(if Internet chat rooms are any guide), grief is not always the prevailing mood. Some anti-globalists have found a kind of consolation even a cause of satisfaction, in these terrible events—that of having been as they see it, proved right. To its fiercest critics, globalization, the march of international capitalism, is a force for oppression, exploitation and injustice. The rage that drove the terrorists to commit their obscene crime was in part, it is argued, a response to that. At the very least, it is suggested, terrorism thrives on poverty and international capitalism, the protesters say, thrives on poverty too. These may be extreme positions, but the minority that holds them is not tiny, by any means. Far more important, the anti-globalists have lately drawn tacit support if nothing else, reluctance to condemn—from a broad range of public opinion. As a result, they have been, and are likely to remain, politically influential. At a time such as this, sorting through issues of political economy may seem very far removed from what matters. In one sense, it is. But when many in the West are contemplating their future with new foreboding, it is important to understand why the skeptics are wrong; why economic integration is a force for good; and why globalization, far from being the greatest cause of poverty, is its only feasible cure. Undeniably, popular support for that view is lacking. In the developed economies, support for further trade liberalization is uncertain; in some countries, voters are downright hostile to it. Starting a new round of global trade talks this year will be struggle, and seeing it through to a useful conclusion will be. The institutions that in most people's eyes represent the global economy—the IMF, the World Bank and the World Trade Organization are reviled far more widely than they are admired; the best they can expect from opinion at large is grudging acceptance. Governments, meanwhile, are accused of bowing down to business: globalization leaves them no choice. Private capital moves across the planet unchecked. Wherever it goes, it bleeds democracy of content and puts "profits before people".

单选题[此试题无题干]

单选题According to the explanation of the scientific rule of experiment in the passage, "hard-and-fast" means experiment procedures ______.

单选题__________ amounts of noxious wastes are dumped into the Songhuajiang River.

单选题If full credits were given to this part, it could ______ a high grade for the student in his physical course. A.belong to B.be due to C.he subject to D.contribute to

单选题Everyone has a legal______to provide the tax office with details of their earnings.(2006年中国矿业大学考博试题)

单选题The report was unusual in that it insinuated corruption on the part of the minister. A, denied B. suggested C. proposed D. stated

单选题Americans were propelled too by a keen sense of ______ about challenging the void.

单选题With all his experience abroad he was a major asset to the company.

单选题All the off-shore oil explorers were in high spirits as they read ______ letters from their families.

单选题Which of the following was NOT true at the time Roosevelt was elected?