单选题The train came to an abrupt stop.

单选题Hack The first big-name hackers include Steve Wozniak, Bill Gates and Linus Torvalds, all now highly recognizable names behind many of the computer technologies used today. These early hackers had a love of technology and a compelling need to know how it all worked, and their goal was to push programs beyond what they were designed to do. Back then, the word "hacker" didn"t have the negative connotation it has today. The original hacker ethic, rooted out of simple curiosity and a need to be challenged, appears to be dead. The objectives of early hackers are a far cry from the goals of today"s hacker. The motivation of the new breed of hackers appears not to be curiosity, or a hunger for knowledge, as it used to be. Instead, most of today"s hackers are driven by greed, power, revenge, or some other malicious intent, treating hacking as a game or sport, employing the tools that are readily available via the Internet. The rate of security attacks is actually outpacing the growth of the Internet. This means that something besides the growth of the Internet is driving the rise in security attacks. Here are some realities you should know about: Operating systems and applications will never be secure. New vulnerabilities will be introduced into your environment every day. And even if you ever do get one operating system secure, there will be new operating systems with new vulnerabilities—phones, wireless devices, and network appliances. Employees will never keep up with security polices and awareness. It doesn"t matter how much you train and educate your employees. If your employees disregard warnings about the hazards of opening questionable e-mail attachments, how are you going to educate them about properly configuring fire-walls and intrusion detection systems for their PCs? Managers have more responsibility than ever. And on top of the realities listed above, security managers are being asked to support increasing degrees of network availability and access. There are some good security measures you can take: Employ a layer 7, full-inspection firewall. Automatically update your anti-virus at the gateway, server and client. Keep all of your systems and applications updated. Hackers commonly break into a Web site through known security holes, so make sure your servers and applications are patched and up to date. Turn off unnecessary network services. Eliminate all unneeded programs. Scan network for common backdoor services—use intrusion detection systems, vulnerability scans, antivirus protection.

单选题Virtually all the children come to school by bus.

单选题First aid may bring about all the following results EXCEPT

单选题The index is the government"s chief gauge of future economic activity.

单选题There are a {{U}}limited{{/U}} number of books on this subject in the library．

单选题 The Doctor in America Self-employed private physicians who charge a fee for each patient visit have been the norm for American medical practice. Most physicians have a contract relationship with one or more hospitals in their community. They refer their patients as needed to the hospital, which usually charges according to the number of days a patient stays and the facilities—X-rays, operating rooms, tests—he or she uses. Some medical doctors are on salary. Salaried physicians may work as hospital staff members, or residents, who are often still in training. They may teach in medical schools, be hired by corporations to care for their workers or work for the federal government's Public Health Service. Physicians are among the best-paid professionals in the United States. In the 1980s, it was not uncommon for medical doctors to earn incomes of more than $100,000 a year. Specialists, particularly surgeons, might earn several times that amount. Physicians list many reasons why they deserve to be so well rewarded for their work. One reason is the long and expensive preparation required to become a physician in the United States. Most would-be physicians first attend college for four years, which can cost nearly $20,000 a year at one of the best private institutions. Prospective physicians then attend medical school for four years. Tuition alone can exceed $10,000 a year. By the time they have obtained their medical degrees, many young physicians are deeply in debt. They still face three to five years of residency (住院医生实习期) in a hospital, the first year as an apprentice physician. The hours are long and the pay is relatively low. Setting up a medical practice is expensive, too. Sometimes several physicians will decide to establish a group practice, so they can share the expense of maintaining an office and buying equipment. These physicians also take care of each other's patients in emergencies. Physicians work long hours and must accept a great deal of responsibility. Many medical procedures, even quite routine ones, involve risk. It is understandable that physicians want to be well rewarded for making decisions which can mean the difference between life and death.

单选题Young people often congregate in the main square in the evenings.

单选题She seemed to have detected some anger in his voice.

单选题Too Many Americans Have Out-of-control High Blood Pressure Nearly 1 in 3 Americans suffers from high blood pressure (hypertension) and many of them don"t have it under control, says a recent study from the Centers for Disease Control and Prevention (CDCP). According to the report, most people with uncontrolled high blood pressure have health insurance and had actually seen a doctor at least twice in the previous year, yet their condition remained unmanaged. Having high blood pressure is a major risk factor for heart disease and stroke; hypertensive people are 4 times more likely to die from a stroke and 3 times more likely to die from heart disease than people with normal pressure, according to CDCP director Dr Thomas Frieden. Together, those two conditions cause nearly 1,000 deaths a day in the US and account for $131 billion in yearly health-care costs. For the report, researchers looked at 2003-2010 data to examine high blood pressure awareness and treatment among adults with uncontrolled conditions. More than 20,000 adult participants answered survey questions and received a physical exam. The data suggest that some 67 million Americans have high blood pressure, and nearly 36 million of them don"t have their condition under control. Among those, about 14 million don"t know they"re hypertensive, nearly 6 million are aware but not receiving treatment, and 16 million know they have high blood pressure and are receiving medication for it but still don"t have their pressure under control. "We have to roll up our sleeves and make high blood pressure control a priority every day, with every patient at every doctor"s visit," said Frieden.

单选题They had a far better (yield) than any other farm miles away around this year.

单选题A notably short man, he plays basketball with his staff several times a week.

单选题Charges for local telephone calls are outrageous .

单选题Stomach Ulcer Stomach ulcers are the cause of severe pain for many people. Doctors have been able to help lessen the pain of ulcers. They could not cure them. Now doctors have discovered a cause of ulcers. This means they may have found a way to cure people who suffer from the stomach pain. Studies show that ten percent of the population will develop an ulcer at some time in their life. So a possible cure is good news for many people. Ulcers are wounds in the stomach that are similar to small cuts or tears. These wounds can harm the tissue in the stomach, the pipe that carries the food to the stomach or parts of the small intestines. Fluids in the stomach then increase the pain of an ulcer. How does a person know he or she has an ulcer? Doctors say most people with ulcers feel a burning pain in their chest or stomach. This pain often is called heartburn. It usually happens before eating or during the night. It causes some people to lose their desire to eat, or they are unable to keep food in their stomachs. Doctors believed that ulcers were caused by unusually strong stomach fluids, which damaged stomach tissue. Now they have discovered that most ulcers are caused by a bacterial organism called Hillico Bactor Pilorie or H Pilorie. H Pilorie bacteria are what make stomach produce extra stomach 1luid. Doctors found that they can kill the bacteria with medicines called antibiotics. Health experts say the discovery of a cure for ulcers can save thousands of millions of dollars in medical costs. They also believe curing ulcers will reduce the number of people who develop stomach cancer. The number of people with stomach cancer is very high in Japan, Southeast Asia and parts of Africa. Doctors say a person is more likely to get an ulcer if someone in his or her family has had one. In fact a person with the family history of ulcers is three times more likely to get one than other people. There are ways people can protect themselves from developing an ulcer. Doctors say it is more important to reduce the amount of strong fluids in the stomach. To do this, doctors say, people should not smoke cigarettes or drink alcohol. And they say people should reduce tension in their lives.

单选题Her mood can be gauged by her reaction to the most trivial of incidents

单选题The city has decided to do away with all the old buildings in its center.

单选题Scientists Develop Ways of Detecting Heart Attack German researchers have come up with a new generation of defibrillators (除颤器) and early-warning software aimed at offering heart patients greater protection from sudden death from cardiac arrest (心脏骤停). In Germany alone around 100,000 people die annually as a result of cardiac arrest and many of these cases are caused by disruption to the heart"s rhythm. Those most at risk are patients who have already suffered a heart attack, and for years the use of defibrillators has proved useful in diagnosing life-threatening disruptions to heart rhythms and correcting them automatically by intervening within seconds. These devices take on a range of functions, such as that of pacemaker. Heart specialists at Freiburg"s University Clinic have now achieved a breakthrough with an implanted defibrillator capable of generating a six-channel electrocardiogram (ECG) within the body. This integrated system allows early diagnosis of acute blood-flow problems and a pending (潜在的) heart attack. It will be implanted in patients for the first time this year. Meanwhile, researchers at the Fraunhofer Institute for Applied Mathematics in Kaiserslautern have developed a new computer software that renders the evaluation of ECG data more precise. The overwhelming majority of patients at risk will not have an implanted defibrillator and must for this reason undergo regular ECGs. "Many of the current programs only take into account a linear correlation of the data. We are, however, making use of a non-linear process that reveals the chaotic patterns of heart beats as an open and complex system," Hagen Knaf says. "In this way changes in the heart beats over time can be monitored and individual variations in patients taken into account." An old study of ECG data, based upon 600 patients who had suffered a subsequent heart attack, enabled the researchers to compare risks and to show that the new software evaluates the data considerably better.

单选题Health Care in the US Health care in the US is well-known but very expensive. Paying the doctor"s bill after a major illness or accident can cost hundreds of thousands of dollars. In the US, a person"s company, not the government, pays for health insurance. Employers have contracts with insurance companies, which pay for all or part of employees "doctors" bills. The amount that the insurance company will pay out to a patient differs wildly. It all depends on what insurance the employer pays. The less the boss pays to the insurance company, the more the employee has to pay the hospital each time he or she gets sick. In 2004, the average worker paid an extra US $558 a year, according to a San Francisco report. The system also means many Americans fall through the cracks (遭遗漏). In 2004, only 61 per cent of the population received health insurance through their employers, according to the report. The unemployed, self-employed, part-time workers and graduated students with no jobs were not included. Most US university students have a gap between their last day of school and their first day on the job. Often, they are no longer protected by their parents" insurance because they are now considered independent adults. They also cannot buy university health insurance because they are no longer students. Another group that falls through the gap of the US system is international students. All are required to have health insurance and cannot begin their classes without it. But exact policies (保险单) differ from school to school. Most universities work with health insurance companies and sell their own standard plan for students. Often, buying the school plan is required, but luckily it"s also cheaper than buying direct from the insurance company.

单选题The demand for videodisc systems is expected to be very great in future years.A. prosperousB. alternateC. comingD. retirement

单选题The policeman wrote down all the particulars of the accident.