单选题The American Cancer Society, which has long been a staunch defender of most cancer screening, is now saying that the benefits of detecting many cancers, especially breast and prostate, have been overstated. It is quietly working on a message, to put on its Web site early next year, to emphasize that screening for breast and prostate cancers and certain other cancers can come with a real risk of over treating many small cancers while missing cancers that are deadly. The cancer society"s decision to reconsider its message about the risks as well as potential benefits of screening was spurred in part by an analysis published Wednesday in The Journal of the American Medical Association, Dr. Otis Brawley, chief medical officer of the cancer society, said. In it, researchers report a 40 percent increase in breast cancer diagnoses and a near doubling of early stage cancers, but just a 10 percent decline in cancers that have spread beyond the breast to the lymph nodes or elsewhere in the body. With prostate cancer, the situation is similar, the researchers report. If breast and prostate cancer screening really fulfilled their promise, the researchers note, cancers that once were found late, when they were often incurable, would now be found early, when they could be cured. A large increase in early cancers would be balanced by a corresponding decline in late-stage cancers. That is what happened with screening for colon and cervical cancers. But not with breast and prostate cancers. Still, the researchers and others say, they do not think all screening will—or should—go away. Instead, they say that when people make a decision about being screened, they should understand what is known about the risks and benefits. For now, those risks are not emphasized in the cancer society"s mammogram message which states that a mammogram is" one of the best things a woman can do to protect her health. " The new analysis finds that prostate cancer screening and breast cancer screening are not so different. Both have a problem that runs counter to everything people have been told about cancer; They are finding cancers that do not need to be found because they would never spread and kill or even be noticed if left alone. That has led to a huge increase in cancer diagnoses because, without screening, those innocuous cancers would go undetected. At the same time, both screening tests are not making much of a dent in the number of cancers that are deadly. That may be because many lethal breast cancers grow so fast they spring up between mammograms. And the deadly prostate ones have already spread at the time of cancer screening. The dilemma for breast and prostate screening is that it is not usually clear which tumors need aggressive treatment and which can be left alone. " The issue here is, as we look at cancer medicine over the last 35 or 40 years, we have always worked to treat cancer or to find cancer early, " Dr. Brawley said. " And we never sat back and actually thought. Are we treating the cancers that need to be treated?"

单选题In English poetry, a quatrain is____.

单选题The widest benefits of the electronic revolution will accrue______the young.

单选题The increase in student number______many problems for the universities.

单选题The main obstacle to Hispanic success in labor market is their______.

单选题The "standard of living" of any country means the average person's share of the goods and services the country produces. A country's standard of living, 【C1】______, depends first and 【C2】______on its capacity to produce wealth. "Wealth" in this sense is not money, for we do not live on money【C3】______on things that money can buy: "goods" such as food and clothing, and "services" such as transport and "【C4】______". A country's capacity to produce wealth depends upon many factors, most of【C5】______have an effect on one another. Wealth depends 【C6】______a great extent upon a country's natural resources. Some regions of the world are well supplied with coal and minerals, and have a fertile soil and a【C7】______climate; other regions possess none of them. Next to natural resources【C8】______the ability to turn them to use. 【C9】______and stable political conditions, and【C10】______from foreign invasion, enable a country to develop its natural resources peacefully and steadily, and to produce more wealth than another country equally well 【C11】______by nature but less well ordered. A country's standard of living does not only depend upon the wealth that is produced and consumed 【C12】______it own borders, but also upon what is indirecdy produced through international trade. For example, Britain's wealth in foodstuffs and other agricultural products would be much less if she had to depend only on【C13】______grown at home. Trade makes it possible for her surplus manufactured goods to be traded abroad for the agricultural products that would【C14】______be lacking. A country's wealth is, therefore, much influenced by its manufacturing capacity, 【C15】______that other countries can be found ready to accept its manufactures.

单选题According to McWhorter, the decline of formal English ______.

单选题Some writers who once greatly______the literary critic have recently recanted, substituting ______for their former criticism.

单选题Besides reducing human labor', robots can also ______.

单选题The grammatical category which is used in the analysis of word classes to identify the syntactic relationship between words in a sentence is ______.

单选题Native Americans probably arrived from Asia in successive waves over several millennia, crossing a plain hundreds of miles wide that now lies inundated by 160 feet of water released by melting glaciers. For several periods of time, the first beginning around 60, 000 B.C. and the last ending around 7, 000 B.C., this land bridge was open. The first people traveled in the dusty trails of the animals they hunted. They brought with them not only their families, weapons, and tools but also a broad metaphysical understanding, sprung from dreams and visions and articulated in myth and song, which complemented their scientific and historical knowledge of the lives of animals and of people. All this they shaped in a variety of languages, bringing into being oral literatures of power and beauty. Contemporary readers, forgetting the origins of western epic, lyric, and dramatic forms, are easily disposed to think of "literature" only as something written. But on reflection it becomes clear that the more critically useful as well as the more frequently employed sense of the term concerns the artfulness of the verbal creation, not its mode of presentation. Ultimately, literature is aesthetically valued, regardless of language, culture, or mode of presentation, because some significant verbal achievement results from the struggle in words between tradition and talent. Verbal art has the ability to shape out a compelling inner vision in some skillfully crafted public verbal form. Of course, the differences between the written and oral modes of expression are not without consequences for an understanding of Native American literature. The essential difference is that a speech event is an evolving communication, an "emergent form", the shape, functions and aesthetic values of which become more clearly realized over the course of the performance. In performing verbal art, the performer assumes responsibility for the manner as well as the content of the performance, while the audience assumes the responsibility for evaluating the performer"s competence in both areas. It is this intense mutual engagement that elicits the display of skill and shapes the emerging performance. Where written literature provides us with a tradition of texts, oral literature offers a tradition of performances.

单选题According to the notions of construction and constituent, the largest construction in a language is sentence.

单选题The screen in the living room has been______in the family. It was my grandmother"s originally.

单选题______was the first Archbishop of Canterbury who was remarkably successful in converting the British king and the nobility to Christianity.

单选题______ is generally accepted, economic growth is determined by the smooth development of production.

单选题Anyone who has any understanding of China will agree that we will be able to achieve a soft landing, supported by buoyant domestic demand.

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Tragedy describes the______of a great individual because he has transgressed against the great moral principles which govern the universe.

单选题In one sense ______ wrote all his life about one theme, which is neatly summed up in the famous phrase "grace under pressure" , and created one hero who acts that theme out.