单选题Obviously these are all factors affecting smooth operation, but the underlying problem is still to be identified.(2004年秋季电子科技大学考博试题)

单选题Like many other aspects of the computer age, Yahoo began as an idea, (1) into a hobby and lately has (2) into a full-time passion. The two developers of Yahoo, David Filo and Jerry Yang, Ph.D. candidates (3) Electrical Engineering at Stanford University, started their guide in April 1994 as a way to keep (4) of their personal interest on the Internet. Before long they (5) that their homebrewed lists were becoming too long and (6) Gradually they began to spend more and more time on Yahoo. During 1994, they (7) yahoo into a customized database designed to (8) the needs of the thousands of users (9) began to use the service through the closely (10) Internet community. They developed customized software to help them efficiently locate, identify and edit material stored on the Internet.

单选题Linda ______ at the dance tonight, nor will Peter.

单选题{{B}}Text 2{{/B}} It used to be so straightforward. A team of researchers working together in the laboratory would submit the results of their research to a journal. A journal editor would then remove the authors' names and affiliations from the paper and send it to their peers for review. Depending on the comments received, the editor would accept the paper for publication or decline it. Copyright rested with the journal publisher, and researchers seeking knowledge of the results would have to subscribe to the journal. No longer. The Internet—and pressure from funding agencies, who are questioning why commercial publishers are making money from government-funded research by restricting access to it—is making access to scientific results a reality. The Organization for Economic Co-operation and Development (OECD) has just issued a report describing the far-reaching consequences of this. The report, by John Houghton of Victoria University in Australia and Graham Vickery of the OECD, makes heavy reading for publishers who have, so far, made handsome profits. But it goes further than that. It signals a change in what has, until now, been a key element of scientific endeavor. The value of knowledge and the return on the public investment in research depends, in part, upon wide distribution and ready access. It is big business. In America, the core scientific publishing market is estimated at between $ 7 billion and $ 11 billion. The International Association of Scientific, Technical and Medical Publishers says that there are more than 2 000 publishers worldwide specializing in these subjects. They publish more than 1.2 million articles each year in some 16 000 journals. This is now changing. According to the OECD report, some 75% of scholarly journals are now online. Entirely new business models are emerging; three main ones were identified by the report's authors. There is the so-called big deal, where institutional subscribers pay for access to a collection of online journal titles through site-licensing agreements. There is open-access publishing, typically sup- ported by asking the author (or his employer) to pay for the paper to be published: Finally, there are open-access archives, where organizations such as universities or international laboratories support institutional repositories. Other models exist that are hybrids of these three, such as delayed open-access, where. journals allow only subscribers to read a paper for the first six months, before making it freely available to everyone who wishes to see it. All this could change the traditional form of the peer- review process, at least for the publication of papers.

单选题Neither John nor his brothers bought what ______ needed.

单选题Having a few too many drinks can mean more than just a blackout or a bad hangover. People who engage in binge drinking are courting danger, experts warn. Binge drinking is most common at colleges and universities, where many adults treat drinking to excess as a rite of passage. A 1997 study from the Harvard School of Public Health reports that 42. 7% of all college students engage in binge drinking. The well-publicized deaths of several college students from binge drinking in 1997 highlights the risks. An 18-year-old freshman at the Massachusetts Institute of Technology drank himself into a coma and died. A 20-year-old fraternity pledge at Louisiana State University died from alcohol poisoning. "Alcohol is always toxic. It's really a poison, " said Steven Schandler, professor of psychology at Chapman University and chief of addiction research at the Long Beach Veterans Affairs Health Care System, who added that binge drinking can lead to alcohol poisoning. "Because it's a poison, like any other poison, if you take in a little bit, you might tolerate it, but if you take in a lot, you might die. " Administrators and doctors say that college freshmen are especially at risk for alcohol poisoning, in part because they often lack the maturity to refrain or stop. And for some who may be new to drinking, their bodies have a relatively low tolerance for alcohol. But problems with alcohol aren't limited to teenagers and young adults. A 39-year-old Buena Park man recently recalled that two days of steady imbibing on a trip to Las Vegas several years ago left him in bad shape. Doctors say blood alcohol levels of about 4% — five times the legal intoxication limit of 0. 8%— can induce potentially lethal side effects in most people. Alcoholics have higher limits. Although not well understood, enzymes that break down and expel alcohol in the liver and kidneys do so more effectively in seasoned drinkers, allowing them to tolerate more, Schandler said. Regardless of a person's tolerance, alcohol exerts its influence when the amount of alcohol taken in exceeds the amount that the body can digest. At that point, alcohol passes from the bloodstream into the brain and begins its attack. Alcohol first affects the brain's cortex, which controls more sophisticated thought processes. That's why people generally become less inhibited under the influence of alcohol, and some are more willing to try things that could be dangerous to themselves or others. Coordination, mainly controlled by the cerebellum, is the next to go, leading to slurred speech and difficulty walking in a straight line. As excessive drinking continues, alcohol moves deeper into the brain until "it gets to the very basic structure of the brain stem that affects things like respiration and heart beat, " said Dr. Bret Ginther, an assistant clinical professor of emergency medicine at UC Irvine. At that point, people may pass out or fall into a coma. Their vital signs may weaken. "The most common cause of death from alcohol poisoning is respiratory arrest, " said Ginther. Eventually, the heart simply stops. Getting to that point is fairly unusual. But Ginther said that at least once or twice a month, patients are brought into the emergency room at UCI Medical Center in Orange suffering from alcohol poisoning. College officials say they are always on the lookout for alcohol abuse but say there is no fail-safe method to keep students from drinking. Many colleges try to educate students, especially those caught drinking illegally or causing disruptions. The Higher Education Center for Alcohol and Other Drug Prevention in Newton, Mass, advocates a community-based approach that includes administrators, faculty, police and businesses in the fight to curb binge drinking, in part by being on alert for people abusing alcohol. The center also stresses the importance of parental guidance and urges parents to have frank discussions with their children about excessive drinking.

单选题In Krashen" s monitor theory, "i" in "i +1" hypothesis of second language acquisition refers to ______.(对外经贸2006研)

单选题In all the cities that have already banned smoking in public venues it is still very difficult to prohibit smoking in places such as restaurants the owners do not want to offend their customers.

单选题It can be inferred from the passage that tile company

单选题The student"s aggressive personality kept him from having many friends.

单选题After the Arab states won independence, great emphasis was laid on expanding education, with girls as well boys ______to go to school.

单选题She sat in the corner of the room, with tears ______ down her cheeks. A. run B. to run C. ran D. running

单选题It is ______ to stare directly at the sun. A. harmful B. harmless C. comfortable D. safe

单选题In order to increase the number of female representatives, the selection committee decided to ______ in favor of women for three years.

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单选题Next week, the European Parliament will debate stringent regulation of a number of effective pesticides. If this regulation is passed, the consequences will be devastating. In the 1960s, widespread use of the potent and safe insecticide DDT led to eradication of many insect-borne diseases in Europe and North America. But based on no scientific evidence of human health effects, the U. S. Environmental Protection Agency banned DDT, and its European counterparts followed suit. Subsequently, more than 1 million people died each year from malaria—but not in America or Europe. Rather, most of the victims were children and women in Africa and Asia. Today, even while acknowledging that indoor spraying of small amounts of DDT would help prevent many deaths and millions of illnesses, nongovernmental organizations continue—with great success—to pressure African governments not to allow its use. In order to stave off such pressure, African public health officials cave, and their children die needlessly. Yet, rather than learning the tragic lesson of the DDT ban, the European Union wants to extend this unscientific ban to other effective insecticides, including pyrethroids and organophosphates—further undercutting anti-malarial efforts. The currently debated regulation would engender a paradigm shift in the regulation of chemicals, from a risk-based approach—based on real world exposures from agricultural applications—to a hazard-based standard, derived from laboratory tests and having little or no basis in reality as far as human health is concerned. Of course, this is fine with anti-chemical zealots. Their concern is bringing down chemical companies in the name of "the environment" —tough luck if African children have to be sacrificed to their agenda, as was the case with DDT(which is still banned in the EU and not under consideration in the current debate). Most poignantly, the fight against malaria and other insect-borne tropical diseases would take another hit, with resulting illness, disability and death disproportionally affecting children under five and pregnant women. And what, after all, is the "danger" of these chemicals being debated? In fact, there is no evidence to support the contention that insecticides pose a health threat to humans. Even DDT, one of the most studied chemicals of all time, has been conclusively shown to be safe for humans at all conceivable levels of exposure sufficient to control malaria and save millions of lives.

单选题The question of whether war is inevitable is one which has concerned many of the world"s great writers. Before considering this question, it will be useful to introduce some related concepts. Conflict, defined as opposition among social entities directed against one another, is distinguished from competition, defined as opposition among social entities independently striving for something which is in inadequate supply. Competitors may not be aware of one another, while the parties to a conflict are. Conflict and competition are both categories of opposition, which has been defined as a process by which social entities function in the disservice of one another. Opposition is thus contrasted with cooperation, the process by which social entities function in the service of one another. These definitions are necessary because it is important to emphasize that competition between individuals or groups is inevitable in a world of limited resources, but conflict is not. Conflict, nevertheless, is very likely to occur, and is probably an essential and desirable element of human societies. Many authors have argued for the inevitability of war from the premise that in the struggle for existence among animal species, only the fittest survive. In general, however, this struggle in nature is competition, not conflict. Social animals, such as monkeys and cattle, fight to win or maintain leadership of the group. The struggle for existence occurs not in such fights, but in the competition for limited feeding areas and for occupancy of areas free from meat-eating animals. Those who fail in this competition starve to death or become victims to other species. This struggle for existence does not resemble human war, but rather the competition of individuals for jobs, markets, and materials. The essence of the struggle is the competition for the necessities of life that are insufficient to satisfy all. Among nations there is competition in developing resources, trades, skills, and a satisfactory way of life. The successful nations grow and prosper; the unsuccessful decline. While it is true that this competition may induce efforts to expand territory at the expense of others, and thus lead to conflict, it cannot be said that war-like conflict among nations is inevitable, although competition is.

单选题It is essential that mankind ______ ways and means to protect the environment.

单选题All things ______, her paper is of great value.