单选题The rules are too （rigid） to allow for humane error.

单选题The most (crucial) problem any economic system faces is how to use its scarce resources.

单选题Listening to Birdsong A male zebra finch (雀科鸣鸟) chirps (鸣) away to himself. Suddenly he notices a female bird nearby. He realizes he has an audience and immediately changes his song. Can the female tell the difference in his performance? According to a new study, the female zebra finch knows. And she prefers the special trills he creates when he sings to her. A male zebra finch changes his song when singing to a female in ways that people can barely detect. But the female finch can tell the difference. Scientists had noticed slight variations in the songs of male zebra finches based on whether they were singing alone or whether there was a female (and potential mate) nearby. With an audience, the males sped up the pace of their songs and controlled the notes they used. For this study, researchers Sarah C. Woolley and Allison Doupe, at the University of California, San Francisco, decided to focus attention on the listening females, which have not been well studied in the past. In the study, Woolley and Doupe set up a long cage with a sound speaker at each end. One broadcast the sound of a male zebra finch singing to himself, like someone singing in the shower. The other speaker broadcast a male performing for a female audience, as if he was giving a concert. Female birds were placed between the two speakers. Some of the birds had mates, others didn"t. The females shifted around a bit, and then most of them hopped over to sit beside just one speaker. All the birds that made a clear choice liked songs meant for a female audience, even if they"d never met the male. Mated females also had a chance to listen to two different performance songs, one from an unknown male, and one from their mate. They spent more time listening to the concert version of their mates" songs, this suggests that after a while, females learn to recognize and prefer the songs of their mates. Scientists then studied the brains of the females. They found certain areas of the brain perked up (活跃起来) when the birds listened to the concert songs. These brain areas may be involved in recognizing and evaluating the songs, and storing the memories of them. This research deals with what"s called directed communication, when the communicator, or sender, focuses the message for a specific audience. One example is the way morns speak to their babies. Mothers around the world use the same sort of high-pitched sing-song chatter (喋喋不休), and the babies respond best to those sounds. Songbirds are one of the only other species known to learn their communication, in this case their songs.

单选题Thirst for Oil Worldwide every day, we devour the energy equivalent of about 200 million barrels of Oil. Most of the energy on Earth comes from the Sun. In fact enough energy from the Sun hits the planet"s surface each minute to cover our needs for an entire year, we just need to find an efficient way to use it. So far the energy in oil has been cheaper and easier to get at. But as supplies dwindle, this will change, and we will need to cure our addiction to oil. Burning wood satisfied most energy needs until the steam-driven industrial revolution, when energy-dense coal became the fuel of choice. Coal is still used, mostly in power stations, to cover orle quarter of our energy needs, but its use has been declining since we started pumping up oil. Coal is the least efficient, unhealthiest and most environmentally damaging fossil fuel, but could make a comeback, as supplies are still plentiful; its reserves are five times larger than oil"s. Today petroleum, a mineral oil obtained from below the surface of the Earth and used to produce petrol, diesel oil and various other chemical substances, provides around 40% of the world"s energy needs, mostly fuelling automobiles. The US consumes a quarter of all oil, and generates a similar proportion of greenhouse gas emissions. The majority of oil Comes from the Middle East, which has half of known reserves. But other significant sources include Russia, North America, Norway, Venezuela and the North Sea. Alaska"s Arctic National Wildlife Refugel could be a major new US source, to reduce reliance on foreign imports. Most experts predict we will exhaust easily accessible reserves within 50 years, though opinions and estimates vary. We could fast reach an energy crisis in the next few decades, when demand exceeds supply. As conventional reserves become more difficult to access, others such as oil shares and tar sands may be used instead. Petrol could also be obtained from coal. Since we started using fossil fuels, we have released 400 billion tonnes of carbon, and burning the entire reserves could eventually raise world temperatures by 13℃. Among other horrors, this would result in the destruction of all rainforests and tile inching of all Arctic ice.

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

单选题 阅读下面这篇短文，短文后列出了7个句子，请根据短文的内容对每个句子做出判断。 {{B}}Breakfast{{/B}} Studies show that children who eat breakfast do better in school. It doesn't take much further thought to believe that adults will feel better and perform better at work as well. Whether you work at home, on the farm, at the office, at school, or on the road, it is not a good idea to skip (故意略去) breakfast. If we don't eat breakfast, we are likely to become tired when our brains and bodies run Iow on fuel. By mid-morning, a lot of us grab a cup of coffee, or wolf down a sugary candy bar to wake up again. This might work for a few minutes, but by lunchtime we are hungry, bad-tempered, and perhaps our mood might make us a little more likely to make unhealthy choices at lunch. Eating a good breakfast sets the tone for the rest of the day. People who eat breakfast are generally more likely to maintain a healthy weight. Many people believe that they will lose weight if they skip meals, but that isn't a good idea. The body expects to be refueled a few times a day, so start with a healthy breakfast. A healthy breakfast should contain some protein (蛋白质) and some fiber (纤维). Protein can come from meat, eggs, beans, or soy (大豆). Fiber can be found in whole cereals (谷物), grains or in fruits. A good example of a healthy breakfast might be something simple like a hard boiled egg, an orange, and a bowl of whole grain cereal with soy milk.

单选题She stood there, trembling with fear. A. jumping B. crying C. moving D. shaking

单选题The bad news upset me very much.

单选题下面有3篇短文，每篇短文后有5道题。请根据短文内容，为每题确定1个最佳选项。{{B}}第一篇{{/B}} {{B}}US States Do Poorly in Women's Health{{/B}} Not a single US state meets basic federal goals for women's health, and the nation as a whole fails except in two areas— mammograms (乳腺X光照片) and dental (牙齿的) check-up—researchers said on Thursday. Millions of women lack health insurance, and states make it difficult to enroll(加入)in Medicaid, the state-federal health insurance plan for the poor, according to the report. And few states are doing anywhere near enough to help women quit smoking—the leading cause of death in the United States. "The nation as a whole and the individual States fall short of meeting national goals," reads the report put together by the National Women's Law Center and the Oregon Health ＆ Science University. "These health goals provide a road map for assessing the status of Women's health." Of 27 measures examined by the group, from screening for diseases to actually treating them, the nation passes on only two, the researchers said. "The nation is so far from the health goals that it receives an overall grade of' unsatisfactory'," they wrote. The problem seems to be a lack among states of an overall plan for health in general, the NWLC said. "State policy makers' piecemeal (一件一件做的) approach to our health care crisis has resulted in a complex and ineffective system that fails to meet the health care needs of women, "Judy Waxman, NWLC Vice President for Health, said in a statement. "Lawmakers need to take a comprehensive, long-term approach to meeting women's health needs and tackle this serious problem that troubles so many families."

单选题They have {{U}}made up his mind{{/U}} to give up smoking.

单选题John is eligible for this job. A. accepted B. qualified C. rejected D. recommended

单选题I can no longer put up with his rudeness.

单选题The book made a great {{U}}impact{{/U}} on its readers. A.force B.influence C.surprise D.power

单选题 下面的短文后列出了7个句子，请根据短文的内容对每个句子做出判断：如果该句提供的是正确信息，请选择A；如果该句提供的是错误信息，请选择B；如果该句的信息文中没有提及，请选择C。 {{B}}Sleep Problems Plague the Older Set{{/B}} Older Americans often have difficulty getting a good night's rest. It's a huge quality-of-life problem, experts say, because contrary to popular belief, seniors require about the same amount of sleep as younger adults. "Sleep problems and sleep disorders are not an inherent (固有的) part of aging," said Dr. Harrison G. Bloom, an associate clinical professor of geriatrics (老年病学) and medicine at the Mount Sinai School of Medicine in New York City. "It's pretty much of a myth that older people need less sleep than younger people." Yet, in a study published recently in The American Journal of Medicine, researchers found that more than half of older Americans have problems getting the sleep they need. Older people tend to have "sleep fragmentation," meaning they wake up more often during the night, said study author Dr. Julie Gammack, an assistant professor of medicine in the Division of Geriatric Medicine at St. Louis University. They also seem to get less "REM" sleep, the type of sleep during which rapid eye movement occurs, Bloom added. It's unclear what role these naturally occurring changes in sleep patterns have on a person's quality of life, Bloom said "What is important, though, is that older people often have actual sleep disorders and problems with sleep," he said. And, experts say, there is usually more than one cause. "Sleep trouble in older adults is typically associated with acute and chronic illnesses, including specific sleep disorders like sleep apnea (呼吸暂停) and restless leg syndrome that appear with greater frequency in older populations," said Michael V. Vitiello, a professor of psychiatry and behavioral sciences and associate director of the University of Washington's Northwest Geriatric Education Center. Taking multiple medications, as many older people do, can also lead to fatigue and "hypersomnia," or being tired all the time, Bloom added. Another big problem, he noted, is depression and anxiety. "Those are very commonly associated with sleep problems." Despite the prevalence (流行) of sleep difficulties in older adults, many patients aren't getting the help they need As a result, problems like insomnia (失眠), restless leg syndrome and sleep apnea are underdiagnosed and undertreated, Bloom said.

单选题They only have a Ulimited/U amount of time to get their points across.

单选题There was a profound silence after his remark.

单选题If language were for {{U}}nothing{{/U}} but the communication of warnings and weather reports, an artifical international language would do nicely.

单选题He has a Upassionate/U interest in music.

单选题The goal for each player in the game of chess is to trap the other player's king into a position from which escape is impossible. A. skill B. aim C. interest D. trend

单选题Her behavior is extremely childish .