单选题When lava cools, it becomes

单选题John doesn’t believe in traditional medicine ; he has some remedies of his own.A. standardB. regularC. routineD. conventional

单选题Winston Churchill gave a {{U}}moving{{/U}} speech.

单选题It's {{U}}prudent{{/U}} to start any exercise program gradually at first.

单选题The psychiatrists declared the killer insane.A. violentB. crazyC. uneducatedD. innocent

单选题Screen Test Every year millions of women are screened with X-rays to pick up signs of breast cancer. If this happens early enough, the disease can often be treated 1 . According to a survey published last year, 21 countries have screening programmes. Nine of them, including Australia, Canada, the U.S. and Spain, 2 women under 50. But the medical benefits of screening these younger 3 are controversial, partly because the radiation brings a small risk of inducing cancer. 4 , younger women must be given higher doses of X-rays because their breast tissue is denser. Researchers at the Polytechnic University of Valencia analyzed the effect 5 screening more than 160,000 women at 11 local clinics. After estimating the women"s cumulative dose of radiation, they used two models to calculate the number of extra cancers this 6 cause. The mathematical model recommended by Britain"s National Radiological Protection Board (NRPB) predicted that the screening programme would 7 36 cancers per 100,000 women, 18 of them fatal. The model preferred by the UN Scientific Committee on the Effects of Atomic Radiation 8 a lower figure of 20 cancers. The researchers argue that the level of radiation-induced cancers is "not very significant" 9 to the far larger number of cancers that are discovered and treated. The Valencia programme, they say, detects between 300 and 450 10 of breast cancer in every 100,000 women screened. But they 11 that the risk of women contracting cancer from radiation could be reduced by between 40 and 80 percent if screening began at 50 instead of 45, because they would be exposed to 12 radiation. The results of their study, they suggest, could help "optimise the technique" for breast cancer screening. " 13 is a trade-off between the diagnostic benefits of breast screening and its risks," admits Michael Clark of the NRPB. But he warns that the study should be interpreted with caution. "On the 14 of the current data, for every 10 cancers successfully detected and prevented there is a risk of 15 one later in life. That"s why radiation exposure should be minimised in any screening programme."

单选题The curious look from the strangers around her made her feel uneasy .

单选题Seasonal variations in tides are due mainly to the gravitational pull of the moon.A. merelyB. mostlyC. likewiseD. somewhat

单选题Many city dwellers are turning vacant lots into thriving gardens. A. costly B. empty C. small D. shady

单选题Why is the Native Language Learnt So Well How does it happen that children learn their mother tongue so well? When we compare them with adults learning a foreign language, we often find this interesting fact. A little child without knowledge or experience often succeeds in a complete mastery of the language. A grown-up person with fully developed mental powers, in most case, may end up with a faulty and inexact command. What accounts for this difference? Despite other explanations, the real answer in my opinion lies partly in the child himself, partly in the behavior of the people around him. In the first place, the time of learning the mother tongue is the most favorable of all, namely, the first years of life. A child hears it spoken from morning till night and, what is more important, always in its genuine form, with the right pronunciation, right intonation, right use of words and right structure. He drinks in all the words and expressions, which come to him in a flash, ever-bubbling spring. There is no resistance: there is perfect assimilation. Then the child has, as it were, private lessons all the year round, while an adult language-student has each week a limited number of hours, which he generally shares with others. The child has another advantage: he hears the language in all possible situations, always accompanied by the right kind of gestures and facial expressions. Here there is nothing unnatural, such as is often found in language lessons in schools, when one talks about ice and snow in June or scorching heat in January. And what a child hears is generally what immediately interests him. Again and again, when his attempts at speech are successful, his desires are understood and fulfilled. Finally, though a child"s "teachers" may not have been trained in language teaching, their relations with him are always close and personal. They take great pains to make their lessons easy.

单选题1. Male and Female Pilots Cause Accidents Differently Male pilots flying general aviating(private) aircraft in the United States are more likely to crash due to inattention or flawed decision - making, while female pilots are more likely to crash from mishandling the aircraft. These are the results of a study by researchers at the Johns Hopkins University Bloomberg School of Public Health. The study identifies the differences between male and female pilots in terms of circumstances of the crash and the type of pilots error involved. "Crashes of general aviation aircraft account for 85 percent of all aviation deaths in the United States. The crash rate for male pilots, as for motor vehicle drivers, exceeds that of crashes of female pilots," explains Susan P. Baker. MPH, professor of health policy and management at the Bloomberg School of Public Health. "Because pilot youth and inexperience are established contributors to aviation crashes, we focused on only mature pilots, to determine the gender differences in the reasons for the crash. " The researchers extracted data for this study from a large research project on pilot aging and flight safety. The data were gathered from general aviation crashes of airplanes and helicopters between 1983 and 1997, involving 144 female pilots and 267 reale pilots aged 40 -63. Female pilots were matched with male pilots in a 1 : 2 ratio, by age, classes of medical and pilot certificates, state or area of crash, and year of crash. Then the circumstances of the crashes and the pilot error involved were categorized and coded without knowledge of pilot gender. The researchers found that loss of control on landing or takeoff was the most common circumstance for both sexes, leading to 59 percent of female pilots' crashes and 36 percent of males. Experiencing mechanical failure, running out of fuel, and landing the plane with the landing gear up were among the factors more likely with males ,while stalling(失速) was more likely with females. The majority of the crashes - 95 percent for females and 88 percent for males - involved at least one type of pilot error. Mishandling aircraft kinetics was the most common error for both sexes, but was more common among females( accounting for 81 percent of the crashes)than males (accounting for 48 percent). Males, however, appeared more likely to be guilty of poor decision - making, risk - taking, and inattentiveness, examples of which include misjudging weather and visibility or flying an aircraft with a known defect. Females, though more likely to mishandle or lose control of the aircraft, were generally more careful than their male counterparts.

单选题The moist air of the Pacific Ocean brings a temperate climate to the West Cost of the United States.A. chillyB. moderateC. wetD. soothing

单选题The use of the chemical may present a certain hazard to the laboratory workers. A. protection B. indication C. immunity D. danger

单选题Which of the following statements is INCORRECT?

单选题The reporter was accused of unprofessional {{U}}conduct{{/U}}.

单选题According to the writer, One of the purposes of teaching English is to get students

单选题There is a growing{{U}} gap {{/U}}between the rich and the poor.

单选题阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案。 {{B}} A Country's Standard of Living{{/B}} The "standard of living" of any country means the average person's share of the goods and services the country produces. A country's standard of living, {{U}}(51) {{/U}} , depends first and {{U}}(52) {{/U}} on its capacity to produce wealth. "Wealth" in this sense is not money, for we do not live on money {{U}}(53) {{/U}} on things that money can buy: "goods" such as food and clothing, and "services" such as transport and "entertainment". A country's capacity to produce wealth depends upon many factors, most of {{U}}(54) {{/U}} have an effect on one another. Wealth depends {{U}}(55) {{/U}} a great extent upon a country's natural resources. Some regions of the world are well supplied with coal and minerals, and have fertile soil and a favorable climate; other regions possess none of them. Next to natural resources {{U}}(56) {{/U}} the ability to turn them to use. China is perhaps as well-off {{U}}(57) {{/U}} the USA in natural resources, but suffered for many years from civil and external wars, and {{U}}(58) {{/U}} this and other reasons was {{U}}(59) {{/U}} to develop her resources. Sound and stable political conditions, and {{U}}(60) {{/U}} from foreign invasions, enable a country to develop its natural resources peacefully and steadily, and to produce more wealth than another country equally well favoured by nature but less well ordered. A country's standard of living does not only depend upon the wealth that is produced and consumed {{U}}(61) {{/U}} its own borders, but also upon what is directly produced through international trade. {{U}}(62) {{/U}}, Britain's wealth in foodstuffs and other agricultural products would be much less if she had to depend only on {{U}}(63) {{/U}} grown at home. Trade makes it possible for her surplus manufactured goods to be traded abroad for the agricultural products that would {{U}}(64) {{/U}} be lacking. A country's wealth is, therefore, much influenced by its manufacturing capacity, {{U}}(65) {{/U}} that other countries can be found ready to accept its manufactures.

单选题I’d like to withdraw 500 from my current account

单选题The first ball to drop - an illuminated 400 - pound iron - and - wood globe—was lowered from a flagpole. Tradition took root and the ball has announced a new beginning almost every year since—in 1942 and 1943, during World War II, the ball was temporarily put out of commission by a war - time" dimout. "Instead crowds gathered in the square and observed a moment of silence before cheering. Although the newspaper moved to a different location in 1914,the ball remained a Times Square tradition, with several redecorations along the way. @In 1955 it slimmed down to a 200 - pound aluminum(铝) globe, and remained that way until the 1980s when red lights and a green stem were added to make it an apple promoting the city 's "I Love New York" tourism campaign. That flashy phase ended in 1988 in favor of simple white lights, followed later by rhinestones (莱茵石) with edges and strobes (频闪闪光灯). But the biggest checkup was saved for the ball that would ring in the new millennium. Weighing up to 1,070 pounds, the massive new ball marketed handcrafted Waterford crystal triangles, each with a design symbolizing various messages such as" Hope for Fellowship," "Hope for Wisdom" and" Hope for Abundance. "With minor changes, that. sphere remained through the 2007 festival This year's ball tops out at 12 feet in diameter (double the size of previous balls) and weighs11, 875 pounds; it sparkles with 32,256 LED lights and 2,668 crystals. It's not the only thing that's gotten bigger since the 1900s;a crowd estimated at a million people will be celebrating in Times Square on Dec. 31st, and millions more will be watching worldwide. What makes this year's ball special compared with the other ones?A. It is a worldwide attraction.B. There are crystals on it.C. It's twice the size of other ones.D. It sparkles with lights.