单选题In his ______ to further his knowledge of the universe, man has now begun to explore space. A. attempt B. expedition C. trial D. chase

单选题The earthquake that occurred in India this year was a major calamity in which a great many lives were lost.

单选题In the author's opinion, the reason for people's discontent about their health condition consists in______.

单选题Great works are performed not by strength but by persistence.

单选题I disapprove of diets so strongly because I think it's wrong suddenly to ______ your body of certain foods.

单选题______ mother-to-be Cherie Blair stunned the party by wearing a sensational violet silk trouser suit which she had specially made for the big night. A. Radial B. Radiant C. Radical D. Racial

单选题Anthropologists, psychologists and others have begun seeking the roots of ambition in family, culture, gender, genes and more. They have by no means thrown the curtain all the way back, but they have begun to part it. If humans are an ambitious species, it's clear we're not the only one. Many animals are known to signal their ambitious tendencies almost from birth. Even before wolf pups are weaned, they begin sorting themselves out into alphas and all the others. The alphas are quicker, more curious, greedier for space, milk, Mom--and they stay that way for life. Alpha wolves wander widely, breed annually and may live to a geriatric 10 or 11 years old. Lower-ranking wolves enjoy none of these benefits--staying close to home, breeding rarely and usually dying before they're four. Humans often report the same kind of temperamental determinism. Families are full of stories of the inexhaustible infant who grew up to be an entrepreneur, the phlegmatic child who never really showed much go. But if it's genes that run the show, what explains identical twins--precise genetic templates of each other who ought to be temperamentally identical but often exhibit profound differences in the octane of their ambition? Ongoing studies of identical twins have measured achievement motivation--lab language for ambition--in identical siblings separated at birth, and found that each twin's profile overlaps 30% to 50% of the other's. In genetic terms, that's an awful lot--"a benchmark for heritability", says geneticist Dean Hamer of the U.S. National Cancer Institute. But that still leaves a great deal that can be determined by experiences in infancy, subsequent upbringing and countless other imponderables. Some of those variables may be found by studying the function of the brain. At Washington University in St. Louis, Missouri, researchers have been conducting brain imaging to investigate a trait they call persistence--the ability to stay focused on a task until it's completed just so--which they consider one of the critical engines driving ambition. The researchers recruited a sample group of students and gave each a questionnaire designed to measure persistence level. Then they presented the students with a task--identifying sets of pictures as either pleasant or unpleasant and taken either indoors or outdoors--while conducting magnetic resonance imaging of their brains. The nature of the task was unimportant, but how strongly the subjects felt about performing it well--and where in the brain that feeling was processed--could say a lot. In general, the researchers found that students who scored highest in persistence had the greatest activity in the limbic region, the area of the brain related to emotions and habits. "The correlation was .8 [or 80%]," says professor of psychiatry Robert Cloninger, one of the investigators. "That's as good as you can get." It's impossible to say whether innate differences in the brain were driving the ambitious behavior or whether learned behavior was causing the limbic to light up. But a number of researchers believe it's possible for the nonambitious to jump-start their drive, provided the right jolt comes along. "Energy level may be genetic," says psychologist Simonton, "but a lot of times it's just finding the right thing to be ambitious about." Simonton and others often cite the case of Franklin D. Roosevelt, who might not have been the same President he became--or even become president at all--had his disabling polio not taught him valuable lessons about patience and tenacity.

单选题If you want to get into that tunnel, you have to ______ away all the rocks.

单选题In view of obstruction and Udisappointment/U, the prime minister decided to make parliamentary alliance.

单选题Scientists hope the collision will produce a large crater in the comet's surface in order to reveal the core and give some ______ to the origin of the solar system.

单选题The news reports completely overlooked the more profound political implications of the events.

单选题Some individuals have Uapplied/U "positive thinking" either to particular external circumstances or Uto/U some particular habits or character defects.

单选题The United Nations declared last Friday that Somalia's famine is over. But the official declaration means little to the millions of Somalis who are still hungry and waiting for their crops to grow. Ken Menkhaus, professor of political science at Davidson College, said it was profoundly disappointing to be discussing another Somali famine, after he worked in the country during the 1991 — 1992 one. Each famine, he said, has distinct characteristics, and this one unfold in slow motion over the past couple of years. That's at least partly because the Somali diaspora sent money home that delayed the worst effects. Menkhaus was among four experts on Somalia and famine who spoke at the Radcliffe Gym Monday evening. Who gathered for the event, "Sound the Horn: Famine in the Horn of Africa. " Paul Farmer, Kolokotrones University Professor of Global Health and Social Medicine, drew on his experience treating malnourished people in Haiti, where he has worked for decade, and said the human and social context of home, and aid to families should be part of wearing the child, he said. Similarly, broader agricultural interventions and fair trade policies are needed to boost local agricultural economies. Though famine is often thought of as a natural disaster, Monday's speakers said that is a false impression. Though Somalia suffered through a severe drought, with today's instant communications, transport systems can move massive amounts of food. Given today's global food markets, famine is too often a failure of local government and international response. "In today's 21st-century world, just about everything about famine is man-made. We're no longer in a world of man against nature. " said Robert Paarlberg, adjunct professor of public policy at the Harvard Kennedy School. Ethiopia, which was also affected by the recent drought, fared much better this time because of reforms implemented after the 2001 one. Likewise, Paarlberg said, northern and central Somalia, regions that fall outside of the influence of the Al-Shabaab militia, also fared better. There were several man-made features of this famine, which affected more than 10 million people and killed between 50, 000 and 100, 000, half of them children under age 5. The largest man-made feature was the role of the Al-Shabaab militia that rules the region and that kept food aid from reaching those in need. But the international community isn't blameless. As early as November 2010, an international famine early warning system was predicting the failure of rains in the region, but the international community didn't respond fully until an official famine was declared in July 2011. On top of that, U. S. anti-terrorism laws cut off food aid because Al-Shabaab, listed as a terrorist group, was taking some of it. Though the United Nations has declared the famine over, that was based on statistical measures, such as the number of people dying each day and the number of children who are malnourished. Though the official famine may be over, both U. N. officials and Monday's speakers said the crisis continues for the people of Somalia. Almost a third of the population remains dependent on humanitarian assistance, crops growing from recent rains will take months to reach maturity, and herds of cows, goats, and other animals were greatly reduced during the crisis. Michael Delaney, director of humanitarian response for Oxfam America, warned that the world will have another chance to get its response fight, because the warning signs are pointing to an impending famine in Africa's Sahel, the arid, continent-spanning transition zone just below the Sahara Desert.

单选题A corps of so-called barefoot doctors are trained in Uhygiene/U, preventive medicine, acupuncture, and routine treatment of common diseases.

单选题While admiring that this forecast was ______ uncertain, the scientists warned against treating it as a cry of wolf.

单选题The international Olympic Games, regarded as the world's most prestigious athletic competition, take place once every the four years.

单选题Largely due to the university tradition and the current academic milieu, every college student here works ______.

单选题What things in life are you most desirous ______ attaining?

单选题The first big-name hackers include Steve Wozniak, Bill Gates and Linus Torvalds, all now highly recognisable 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 backer 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. 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 email attachments, how are you going to educate them about properly configuring firewalls 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 your network for common backdoor services, and use intrusion detection systems, vulnerability scans, and anti-virus protection.