单选题The illegal workers are ______.

单选题It is well known that retired workers in China are ______ free medical care.

单选题The central plan, ______ by the government, shows the amount of each goods produced by the various firms and shared among different households for consumption. A. drawn on B. drawn down C. drawn up D. drawn back

单选题The United States Food and Drag Administration has shown itself to be particularly wary with regard to alleged "miracle" drugs in recent times.

单选题Sometimes Americans are said to be______. Perhaps it seems so, but they are probably just having a good time. Just like anywhere else, it takes time to become real friends with people in the U.S.

单选题 The clown's performance was so funny that the audience, adults and children alike, were all thrown into convulsions.

单选题Scientists have long understood that supermassive black holes weighing millions or billions of suns can tear apart stars that come too close. The black hotels gravity pulls harder on the nearest part of the star, an imbalance that pulls the star apart over a period of minutes or hours, once it gets close enough. Scientists say this uneven pulling is not the only hazard facing the star. The strain of these unbalanced forces can also trigger a nuclear explosion powerful enough to destroy the star from within. Matthieu Brassart and Jean-Pierre Luminet of the Observatoire de Paris in Meudon, France, carried out computer simulations of the final moments of such an unfortunate star's life, as it veered towards a supermassive black hole. When the star gets close enough, the uneven forces flatten it into a pancake shape. Some previous studies had suggested this flattening would increase the density and temperature inside the star enough to trigger intense nuclear reactions that would tear it apart. But other studies had suggested that the picture would be complicated by shock waves generated during the flattening process and that no nuclear explosion should occur. The new simulations investigated the effects of shock waves in detail, and found that even when their effects are included, the conditions favor a nuclear explosion. " There will be an explosion of the star — it will be completely destroyed," Brassart says. Although the explosion obliterates the star, it saves some of the star's matter from being devoured by the black hole. The explosion is powerful enough to hurl much of the star's matter out of the black hole's reach, he says. The devouring of stars by black holes may already have been observed, although at a much later stage. It is thought mat several months after the event that rips the star apart, its matter starts swirling into the hole itself. It heats up as it does so, releasing ultraviolet light and X-rays. If stars disrupted near black holes really do explode, then they could in principle allow these events to be detected at a much earlier stage, says Jules Hatpern of Columbia University in New York, US2. "It may make it possible to see the disruption of that star immediately if it gets hot enough," he says. Brassart agrees. "Perhaps it can be observed in the X-rays and gamma rays, but it's something that needs to be more studied," he says. Supernova researcher Chris Fryer of the Los Alamos National Laboratory in Los Alamos, New Mexico, US3, says the deaths of these stars are difficult to simulate, and he is not sure whether the researchers have proven their case that they explode in the process.

单选题It is simply a moral ______ not to segregate children from their peers since they learn by interacting and modeling.

单选题Any property that a bankrupt person may still have is usually divided among the various people to whom money are owed.A.Any property B.may still have C.among D.are owed

单选题John Bowman was given his first job as a secretary because ______ .

单选题It is impossible that the brain,______, will be replaced by computer A. as we know B. which we know C. we know that D. we know

单选题The medieval church condemned man's partaking in ______ pleasures. A. educational B. ascetic C. asexual D. sensual

单选题In managing information resources, the medium may be the key to an effective system. The medium is a vehicle, a tool, or a container for holding information; the information itself is the thing of value. Three popular categories of information media are paper, film, and electronic storage devices. The media choice must not be viewed as a choice among these three, however, it must be viewed as an opportunity to select from a multitude of media possibilities in combinations that build effective systems. In many instances the person responsible for information — resource management is not the person who determines the medium in which information will be created. In such a case, the manager of a firm's information resources faces a challenge in making a significant contribution to the organization's objectives. For effective management of information resources, media conversion may be necessary. Examples include keying or scanning paper documents to convert them to electronic media. Other processes convert electronic media from one format to another. For example, disk files created on one system may not be compatible with another system. Various hardware and software combinations can be used to convert files to formats that equipment will accept. For information generated within organizations, this necessity of making systems compatible may be eliminated by cooperative planning. However, very little control can be exercised over the media used to generate information that comes to your organization from the outside. The medium for information may be selected to satisfy a need that exists when information is created and communicated. For example, a paper record may be created because of its portability and because no special equipment is necessary for later references to that information; electronic transmission may be selected because it is the fastest means of communicating information. A firm may use electronic mail because a network already exists for on-line computer communication. The additional application may cost less than postage to mail paper memos.

单选题 In spite of "endless talk of difference", American society is an amazing machine for homogenizing people. There is "the democratizing uniformity of dress and discourse, and the casualness and absence of consumption" launched by the 19th century department stores that offered "vast arrays of goods in an elegant atmosphere". Instead of intimate shops catering to a knowledgeable elite, these were stores "anyone could enter, regardless of class or background. This turned shopping into a public and democratic act". The mass media, advertising and sports are other forces for homogenization. Immigrants are quickly fitting into this common culture, which may not be altogether elevating but is hardly poisonous. Writing for the National Immigration Forum, Gregory Rodriguez reports that today's immigration is neither at unprecedented level nor resistant to assimilation. In 1998 immigrants were 9.8 percent of population;in 1900,13.6 percent. In the 10 years prior to 1990,3. I immigrants arrived for every 1,000 residents; in the 10years prior to 1890,9. 2 for every 1,000. Now, consider three indices of assimilation--language, home ownership and intermarriage. The 1990 Census revealed that "a majority of immigrants from each of the fifteen most common countries of origin spoke English ' well' or ' very well' after ten years of residence". The children of immigrants tend to be bilingual and proficient in English. "By the third generation, the original language is lost in the majority of immigrant families. "Hence the description of America as a "graveyard" for languages. By 1996 foreign-born immigrants who had arrived before 1970 had a home ownership rate of 75.6 percent, higher than the 69.8 percent rate among native-born Americans. Foreign-born Asians and Hispanics "have higher rates of intermarriage than do U. S-born whites and blacks". By the third generation, one third of Hispanic women are married to non-Hispanics, and 41 percent of Asian-American women are married to non-Asians. Rodriguez note that children in remote villages around the world are fans of superstars like Arnold Schwarzenegger and Garth Brooks, yet "some Americans fear that immigrant living within the United States remain somehow immune to the nation's assimilative power". Are there divisive issues and pockets of seething anger in America? Indeed. It is big enough to have a bit of everything. But particularly when viewed against America's turbulent past, today's social induces suggest a dark and deteriorating social environment.

单选题After several ______ attempts to send the missile into space, the spacecraft was finally launched successfully. A. abortive B. difficult C. experimental D. preliminary

单选题______ flees if one is constantly subjected to demeaning orders.

单选题Although most dreams apparently happen______, dream activity may be provoked by external influences.(2013年北京航空大学考博试题)

单选题Which of the following experimental results, if observed, would most clearly contradict the findings of Victor Emmet?