单选题What can be inferred from the figures in Paragraph 2?

单选题Which of the following best describes the organization of the first paragraph of the text?

单选题Sialic material refers to______.

单选题How does the child develop his perception?

单选题The reason why a good business plan is important is that it can

单选题Just 10 years into a new century, more than two-thirds of the country sees the past decade as a period of decline for the U. S. , according to a new TIME poll that probed Americans on the decade since the tragic events of Sept. 11, 2001. The poll confirms that the country is going through one of its longest sustained periods of unhappiness and pessimism ever. Today"s teenagers hardly remember a time before 9/11, the war on terrorism, the war in Iraq and constant economic upheaval . Baby boomers, the generation known for continuous reinvention, are filled with worry and doubt about their future and the future of their children. It is hard to overstate what a fundamental change this represents. A country long celebrated for its optimism amid adversity is having trouble finding the pluck and the spirit that have seen it through everything from world wars to nuclear threats to space races. The U.S. usually bounces back after a few years of difficulty, such as the Vietnam War, Watergate or recessions. After two or three years of anxiety and worry, the electorate normally returns to its innate optimism. Yet the forces now aligned against the American people seem much more formidable to those we surveyed. According to the poll, only 6% of more than 2, 000 Americans believe the country has completely recovered from the events of 9/11. Some of this pessimism can be tied to fears of more terrorist attacks. Despite the death of Bin Laden, most Americans think another terrorist attack in the U. S. is likely. Americans generally supported the post-9/ll measures to secure the homeland, like those in the Patriot Act, and have confidence in the military to deal with terrorists—and yet they see an attack coming anyway. America"s feelings of invincibility have been replaced by a new sense of inevitable vulnerability. Post-9/11 American also take a "leave-me-alone" attitude toward the rest of world. Most respondents have no desire to be more involved in global affairs. Almost two-thirds (62%) believe the U. S. today is too involved overseas. But whatever the U. S. "s worries about external forces, the biggest threats today are widely regarded as self-made. It"s the enemy within that Americans register the most concern about: runaway deficits, political conflicts, skyrocketing health care costs and other structural problems. If there is widespread agreement that the U. S. is in bad shape, there is also a perception that not everyone has experienced the difficult decade in exactly the same way. Those surveyed say middle-and working-class Americans, followed by seniors and younger people, have borne the brunt of the decline. Yet those surveyed said some demographic groups were better off than they were a decade ago; they say the quality of life has improved most for gays and lesbians, the affluent, Hispanics and immigrants. And while overall the U.S. is seen as becoming more socially and politically tolerant in the past decade, the majority agreed that 9/11 set off a wave of suspicion against Muslim Americans. President Jimmy Carter rather famously gave a speech in mid-1979 suggesting that a crisis of confidence had befallen America. It took several years and a new President to return the country to its optimistic ways. President Bill Clinton faced a similar moment in 1995 and turned the mood of the country around a year later. This poll suggests we are at another malaise moment, one even longer and deeper than the mid-1970s", presenting even greater challenges—and opportunities—for leadership.

单选题It can be inferred from the par

单选题{{B}}Text 2{{/B}} Psychotherapy for as long as nine months is significantly more effective than short-term treatment for alleviating depression associated with bipolar disease, new research suggests. The drugs used to treat depression are of limited use in treating the repeating depressive episodes of bipolar illness, according to background information in the article, published last week in The Archives of General Psychiatry. The researchers studied 293 patients with bipolar disease at 15 medical centers nationwide. They randomly assigned one group of 163 people to one of three kinds of psychotherapy consisting of up to 30 50-minute sessions over nine months. A second group of 130 patients was assigned to "collaborative care," three sessions over six weeks designed to offer a brief version of the most common psychological and behavioral strategies shown to be beneficial in bipolar illness. The participants, whose average age was 40, were followed for one year, and all were also being treated with mood-stabilizing medicines. Cognitive behavioral therapy focuses on challenging and controlling negative thoughts. In interpersonal and social rhythm therapy, patients concentrate on stabilizing daily routines and resolving interpersonal problems. Family therapy engages family members to help solve problems related to the illness, like failing to take medication properly, and to reduce the number of negative family interactions. Therapists at each of the 15 medical centers received brief training in the therapies they administered. "The study included real-world patients experiencing the early phases of a depressive episode," said David J. Miklowitz, the study's lead author. "And the therapists who delivered the treatment were trained by experts in the field with low-intensity training, which is typical of what's available in real-life practice." Recovery rates after one year were a combined average of 64 percent for the intensive therapy groups, but only 52 percent for those who had brief therapy. In any given month, a patient undergoing longer-term therapy was more than one and a half times as likely to be well as one who had short-term treatment. Family therapy was slightly more effective than interpersonal or cognitive behavioral therapy, but the differences among the types of intensive treatment were not statistically significant. "This is a monumental study," said a professor of psychiatry who was not involved in the work. "There are no pharmaceutical companies willing to pay for research in psychotherapy, so we don't have many clinical trials." But, she added: "Psychosocial treatment for bipolar illness is not an alternative to medication. It's a supplement." The cost of long-term therapy is high, and insurance companies are reluctant to cover it. But according to the professor, the cost of not covering it could be higher. "It isn't just the cost of the therapy. It's the long-term cost. Bipolar illness has devastating effects on families as well as on the patients themselves."

单选题The objective of the migrant health program of the United States government is to provide grants for the development and enhancement of high quality health care services in rural areas for migrant and seasonal farm workers and their families so as to raise the status of health care for these people to that of the general population. This amelioration can be achieved by providing comprehensive heahh services, which are made aeeessible to people who move frequently, and by improving the physical environment so as to assure healthful living and working conditions wherever workers are located. Grants are available to state and local health departmenls and other nonprofit agencies, organizations, and institutions. These funds can he used for the following purposes: to establish and operate general family health service facilities and clinics; to provide heahh education, training, and sanitation services to upgrade health conditions; and to initiate preventive health services. Preventive care in the form of immunization programs is the oldest aspect of the program. The program further attempts to promote flexibility in locating health services where they will be accessible at times and places convenient to migrant workers and their families. The family heahh care clinic, with additional outreach services by field nurses and aides who visit migrant families in camps and at their homes for counseling and follow-up, constitutes the newest and most significant innovation in the initiate preventive health services. However, despite the introduction of innovative approaches, heahh care services for migrant workers are still limited and highly inadequate. Although the migrant health program has no fixed matctling ratio, a grantee is required to pay part of the cost, which varies from project to project. Many rural counties do not have enough money to cover matching payments, nor do many states consider migran! workers' health a budget priority. The costsharing requirement limits the potential effectiveness of the program, and literally hundreds of communities with a yearly influx of nngrant workers still lack organized local programs to provide the needed services. A major problem for local or state health agencies is their inability to develop case histories and ongoing communication with migrant workers. Lack of knowledge regarding migrant workers' health needs is another reason for the dearth of services. There has been little communication about health problems among communities, health professionals, and migrant workers themselves. Ignorance of a group's special needs often leads to exclusion and rejection of that group and its prohlems. This is often the case with migrant workers, as evidenced by the enforcement of state residency requirement. It is, of course, impossible for most migrant workers to meet these requirements and become eligible fro" existing state and local heahh and welfare aid.

单选题Simply flipping through a book may not seem like the best way to scan it, but a Japanese research group at Tokyo University has created new software that allows hundreds of pages to be scanned within minutes. Scanning paper is normally a tedious process with each page having to be inserted into a flatbed scanner, but the team led by professor Masatoshi Ishikawa use a high speed camera that takes 500 pictures a second to scan pages as they are flipped. Normal scanners can only scan the information that is actually before them on the page. The new scanner being developed is able to deal with the fact that pages that are being flipped are normally deformed in some fashion. "It takes a shot of the shape, then it calculates the shape and uses those calculations to film the scanning," Ishikawa said, explaining the system used to reconstruct the original page. "As it can film while understanding the underlying shape, it"s very easy to then take the pages that are being scanned and save them as a normal flat copy." The current system is able to scan an average 200～250 page book in a little over 60 seconds using basic computer hardware that is available off-the-shelf. While it now requires extra time to process the scanned images, the researchers hope to eventually make the technology both faster and much smaller. "In the more distant future, once it becomes possible to put all of this processing on one chip and then put that in an iPad or iPod, one could scan just using that chip. At that point, it becomes possible to scan something quickly to save for later reading," Ishikawa said. Being able to scan books with an iPhone may be further off, but Ishikawa says that a commercial version of the large-scale computer based scanning system could be available in two to three years. While the technology has the potential to take paper books into the digital age, it remains to be how publishers will react to people scanning their books while just flipping through them.

单选题Soon after his appointment as secretary-general of the United Nations in 1997, Kofi Annan lamented that he was being accused of failing to reform the world body in six weeks. "But what are you complaining about?" asked the Russian ambassador: "You've had more time than God." Ah, Mr. Annan quipped back, "but God had one big advantage. He worked alone without a General Assembly, a Security Council and [all] the committees." Recounting that anecdote to journalists in New York this week, Mr. Annan sought to explain why a draft declaration on UN reform and tackling world poverty, due to be endorsed by some 150 heads of state and government at a world summit in the city on September 14th- 16th, had turned into such a pale shadow of the proposals that he himself had put forward in March. "With 191 member states", he sighed, "it's not easy to get an agreement." Most countries put the blame on the United States, in the form of its abrasive new ambassador, John Bolton, for insisting at the end of August on hundreds of last minute amendments and a line-by-line renegotiation of a text most others had thought was almost settled. But a group of middle-income developing nations, including Pakistan, Cuba, Iran, Egypt, Syria and Venezuela, also came up with plenty of last-minute changes of their own. The risk of having no document at all, and thus nothing for the world's leaders to come to New York for, was averted only by marathon all-night and all-weekend talks. The 35-page final document is not wholly devoid of substance. It calls for the creation of a Peacebuilding Commission to supervise the reconstruction of countries after wars; the replacement of the discredited UN Commission on Human Rights by a supposedly tougher Human Rights Council; the recognition of a new "responsibility to protect" peoples from genocide and other atrocities when national authorities fail to take action, including, if necessary, by force; and an "early" reform of the Security Council. Although much pared down, all these proposals have at least survived. Others have not. Either they provod so contentious that they were omitted altogether, such as the sections on disarmament and non-proliferation and the International Criminal Court, or they were watered down to little more than empty platitudes. The important section on collective security and the use of force no longer even mentions the vexed issue of pre-emptive strikes; meanwhile the section on terrorism condemns it "in all its forms and manifestations, committed by whomever, wherever and for whatever purposes", but fails to provide the clear definition the Americans wanted. Both Mr. Annan and, more surprisingly, George Bush have nevertheless sought to put a good face on things, with Mr. Annan describing the summit document as "an important step forward" and Mr. Bush saying the UN had taken "the first steps" towards reform. Mr. Annan and Mr. Bolton are determined to go a lot further. It is now up to the General Assembly to flesh out the document's skeleton proposals and propose new ones. But its chances of success appear slim.

单选题If the opinion polls are to be believed, most Americans are coming to trust their government more than they used to. The habit has not yet spread widely among American Indians, who suspect an organization which has so often patronized them, lied to them and defrauded them. But the Indians may soon win a victory in a legal battle that epitomizes those abuses. Elouise Cobell, a banker who also happens to be a member of the Blackfeet tribe in Montana, is the leading plaintiff in a massive class-action suit against the government. At issue is up to ＄10 billion in trust payments owed to some 500,000 Indians. The Suit revolves around Individual Indian Money (11M) accounts that are administered by the Interior Department's Bureau of Indian Affairs (BIA). Back in the 1880s, the government divided more than 11m acres of tribal land into parcels of 80 to 160 acres that were assigned to individual Indians. Because these parcels were rarely occupied by their new owners, the government assumed responsibility for managing them. As the Indians' trustee, it leased the land out for grazing, logging, mining and oil drilling--but it was supposed to distribute the royalties to the Indian owners. In fact, officials admit that royalties have been lost or stolen. Records were destroyed, and the government lost track of which Indians owned what land. The plaintiffs say that money is owing to 500,000 Indians, but even the government accepts a figure of about 300,000. For years, Cobell heard Indians complain of not getting payment from the government for the oil-drilling and ranching leases on their land. But nothing much got done. She returned to Washington and, after a brush-off from government lawyers, filed the suit. Gale Norton, George Bush's interior secretary was charged with contempt in November because her department had failed to fix the problem. In December, Judge Lam berth ordered the interior Department to shut down all its computers for ten weeks because trust-fund records were vulnerable to hackers. The system was partly restored last month and payments to some Indians, which had been interrupted, resumed. And that is not the end of it. Ms Norton has proposed the creation of a new Bureau of Indian Trust Management, separate from the BIA. Indians are cross that she suggested this without consulting them. Some want the trust funds to be placed in receivership, under a neutral supervisor. Others have called for Congress to establish an independent commission, including Indians, to draw up a plan for reforming the whole system. A messy injustice may at last be getting sorted out.

单选题The use of heat pumps has' been held back largely by skepticism about advertisers' claims that heat pumps can provide as many as units of thermal energy for each unit of electrical energy used, thus apparently contradicting the principle of energy conservation. Heat pumps circulate a fluid refrigerant that cycles alternatively from its liquid phase to its vapor phase in a closed loop. The refrigerant, starting as a low-temperature, low-pressure vapor, enters compressor driven by an electric motor. The refrigerant leaves the compressor as a hot, dense vapor and flows through a heat exchanger called the condenser, which transfers heat from the refrigerant to a body or air. Now the refrigerant, as a high-pressure, cooled liquid, confronts a flow restriction which causes the pressure to drop. As the pressure falls, the refrigerant expands and partially vaporizes, becoming chilled. It then passes through a second heat exchanger, the evaporator, which transfers heat from the air to the refrigerant, reducing the temperature of this second body of air. Of the two heat exchangers, one is located inside, and the other one outside the house, so each is in contact with a different body of air: room air and outside air, respectively. The flow direction of refrigerant through a heat pump is controlled by valves. When the refrigerant flow is reversed, the heat exchangers switch function. This flow-reversal capability allows heat pumps--either to heat or cool room air. Now, if under certain conditions a heat pump puts out more thermal energy than it consumes in electrical energy, has the law of energy conservation been challenged? No, not even remotely: the additional input of thermal energy into the circulating refrigerant via the evaporator accounts for the difference in the energy equation. Unfortunately, there is one real problem. The heating capacity of a heat pump decreases as the outdoor temperature falls. The drop in capacity is caused by the lessening amount of refrigerant mass moved through the compressor at one time. The heating capacity is proportional to this mass flow rate: the less the mass of refrigerant being compressed, the less the thermal load it can transfer through the heat-pump cycle. The volume flow rate of refrigerant vapor through the single-speed rotary compressor used in heat pumps is approximately constant., But cold refrigerant vapor entering a compressor is at lower pressure than warmer vapor. Therefore, the mass of cold refrigerant--and thus the thermal energy it carries--is less than if the refrigerant vapor were warmer before compression. Here, then, lies a genuine drawback of heat pumps: in extremely cold climates--where the most heat is needed--heat pumps are least able to supply en6ugh heat.