单选题They have the competence to take this job. A. possibility B. reality C. capacity D. probability

单选题She could fix the machine without referring to the instructions.A. understandingB. observingC. consultingD. obtaining

单选题I propose that we discussed this at the next meeting.

单选题The League of Women Voters is a nonpartisan organization that promotes informed active public participation in government.

单选题Smoking Can Increase Depressive Symptoms in Teens While some teenagers may puff on cigarettes to "self-medicate" against the blues, scientists at the University of Toronto and the University of Montreal have found that smoking may actually (51) depressive symptoms in some teens. "This observational study is one of the few to examine the perceived (52) benefits of smoking among teens," says lead researcher Michael Chaiton, a research associate at the Ontario Tobacco Research Unit of the University of Toronto. " (53) cigarettes may appear to have self-medicating (54) or to improve mood, in the long term we found that teens who started to smoke reported higher depressive symptoms." As part of the study, some 662 high school teenagers completed up to 20 questionnaires (55) their use of cigarettes to affect mood. Secondary schools were selected to provide a mix of French and English participants, urban and rural schools, and schools (56) in high, moderate and low socio-economic neighbourhoods. Participants were divided into three (57) : never smokers; smokers who did not use cigarettes to self-medicate, improve mood or physical (58) ; smokers who used cigarettes to self-medicate. Depressive symptoms were measured using a scale that asked how felt too fired to do things: had (59) going to sleep or staying (60) ; felt unhappy, sad, or depressed; felt hopeless about the future; felt vexed, antsy or tense; and worried too much about things. "Smokers who used cigarettes as mood (61) had higher risks of elevated depressive symptoms than teens who had never smoked," says co-researcher Jennifer O'Loughlin, a professor at the University of Montreal Department of Social and Preventive Medicine. "Our study found that teen smokers who reported emotional benefits from smoking are at higher risk of (62) depressive symptoms." The (63) between depression and smoking exists (64) among teens that use cigarettes to feel better. "It's (65) to emphasize that depressive symptom scores were higher among teenagers who reported emotional benefits from smoking after they began to smoke," says Dr. Chaiton.

单选题We had a long conversation about her parents. A. speech B. question C. talk D. debate

单选题It was obvious that she was not going home.A. probableB. necessaryC. possibleD. evident

单选题Many people were {{U}}injured{{/U}} during the storm.

单选题It is absurd to go out in such terrible weather.

单选题As soon as Linda went into the department that sold raincoats, she sensed there was something unusual in the atmosphere. First of all, there was a salesman there and not a saleswoman. That was very unusual in the women's coat department. The salesman asked if he could be of any help. But when she said she was just looking he did not seem to be listening. He (lid not look very much like a salesman, either. A second later a raincoat caught her eye. Site asked him a question about it. He did not even hear her at first. She asked again. She wanted to know if he had any coats like it with a detachable (可分离的) lining. He did not seem to understand what a detachable lining was. She explained. Then she went on looking. She noticed that the salesman seemed to be watching another customer in the department all the time. The other customer, a middle-aged woman, left the department. The salesman immediately went to the phone and told somebody on the other end that the woman had gone and had definitely taken two leather belts without paying for them. Then he turned to Linda and explained that he was not a salesman at all but a store detective. Later, Linda read in the paper that a woman had been arrested for stealing some belts front a department store, or, in other words, for shoplifting.

单选题Scott seized the opportunity to present his proposal to the director. A. realized B. grasped C. rendered D. delivered

单选题Virus Linked to Prostate (前列腺) Tumours The researchers from the University of Utah and Columbia University medical schools found the virus in 27% of the 200 cancerous prostates they looked at. They say it was associated with more aggressive tumours and found in only 6% of non - cancerous prostates. The finding raises the prospect of one day producing a vaccine to protect against prostate cancer. This is the first report to link XMRV (Xenotropic murine leukaemia virus--related virus) to human cancers. XMRV is a retrovirus like HIV which works by inserting a copy of its own DNA into the chromosomes (染色体) of a cell they infect. When this occurs to a gene that regulates cell growth, it can disrupt the normal development of the cell. Dr Helen Rippon, Head of Research Management at The Prostate Cancer Charity, said the research was intriguing (吸引人的) but posed several key questions about the role the infection plays in prostate cancer. He said: " Around the world, extensive work is being undertaken to identify risk factors for prostate cancer which will enable treatments and tests for the disease to be refined. " "It is critically important to identify key triggers of prostate cancer to improve early detection of the disease in men with potentially life threatening prostate cancer. " XMRV is known to cause leukemia (白血病) and other tumours in animals. Dr Ila Singh, who led the study from the pathology department at the University of Utah, said: "We still don't know that this virus causes cancer in people, but that is an important question we are going to investigate. " Dr Chris Parker, Cancer Research UK' s prostate cancer expert at the Institute of Cancer Research said: "This exciting study raises the possibility that the virus might contribute to the development of some prostate cancers. " "In the future, if it turns out to he true, then we, could speculate about the possibility of vaccination to protect against prostate cancer, similar to the approach now used to prevent cervical cancer (子宫颈癌). /

单选题Which of the following is NOT mentioned as a possible cure for negative stress?

下面的短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为第2～?段名其中4段选择1个最佳标题；(2)第27～30题要求从所给的6个选项中为每个句子确定1个最佳选项。 {{B}}Screen Test{{/B}}1. 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 successfully. According to a survey published last year, 21 countries have screening programmes. Nine of them, including Australia, Canada, the US and Spain, screen women under 50.2. But the medical benefits of screening these younger women are controversial, partly because the radiation brings a small risk of inducing cancer. Also, younger women must be given higher doses of X-rays because their breast tissue is denser.3. Researchers at the Polytechnic University of Valencia analysed the effect of 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 would cause.4. The mathematical model recommended by Britain's National Radiological Protection Board (NRPB) predicted that the screening programme would cause 36 cancers per 100,000 women, 18 of them fatal. The model preferred by the UN Scientific Committee on the Effects of Atomic Radiation led to a lower figure of 20 cancers.5. The researchers argue that the level of radiation-induced cancers is "not very significant" compared to the far larger number of cancers that are discovered and treated. The Valencia programme, they say, detects between 300 and 450 cases of breast cancer in every 100,000 women screened.6. But they point out 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 less radiation. The results of their study, they suggest, could help "optimise the technique" for breast cancer screening.7. "There 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 basis of the current data, for every 10 cancers successfully detected and prevented there is a risk of causing one later in life. That's why radiation exposure should be minimized in any screening programme."

Timothy Stow of Inver Grove Heights, Minn. worked hard, exercised often and thought he got plenty of sleep. Yet he never felt rested. The 20-year-old salesman dozed off during meetings and had four car accidents after falling asleep at the wheel. {{U}}(46) {{/U}} {{U}} (47) {{/U}}Electrodes affixed from head to toe kept track of all activity in his brain, heart, eyes, faces, arms and legs. {{U}} (48) {{/U}} When he slept, the soft tissue at the back of his throat, near the base of his tongue, collapsed against itself, blocking air intake. Each time his breath was cut off—about 100 times an hour—his brain would alert him to awaken and breathe. He never woke to full consciousness, but neither did he fall into a deep, restful sleep. Sleep apnea afflicts millions of Americans, typically middle-aged, overweight men. The problem begins gradually with loud and prolonged snoring. {{U}}(49) {{/U}} In severe cases, the victim spends most of his sleep time not breathing. Doctors at the center gave Stow a Continuous Positive Airway Pressure (CPAP) device. {{U}}(50) {{/U}} A. Now when he retires, he straps over his nose a soft rubber mask connected to a small unit that supplies just enough air pressure to hold his airway open so he can breathe continuously. B. Finally his doctor sent him to the Minnesota Regional Sleep Disorders Center in Minneapolis. C. Later, at the end of each run of snores comes a brief breath-holding spell. D. Doctors soon realized that Stow was a victim of sleep apnea. E. Many people have chronic sleep problems. F. Placed in a quiet room, Stow went to sleep at his usual time.

Some people can quite accurately time the end of their night's sleep at will, without using an alarm clock, demonstrating that it is possible to voluntarily control a state of consciousness that is characterized by a loss of volition and attentional guidance. Here we show that the expectation that sleep will come to an end at a certain time induces a marked increase in the concentration of the hormone adrenocorticotriopin(促肾上腺皮质激素) in the blood one hour before waking. The regulation of adrenocorticotropin release during nocturnal sleep is therefore not confined to daily rhythms; {{U}}(46) {{/U}} {{U}}(47) {{/U}} Normally, the release of adrenocorticotropin and cortisol(皮质醇)increases during late stages of sleeping, reaching a daily maximum at the time of spontaneous waking. Adrenocorticotropin and cortisol are also released from the pituitary-adrenal system in a major adaptive response to stress, and are secreted in anticipation of stressful events. We investigated whether the increase in the secretion of pituitary-adrenal hormones during the late stages of sleeping in part reflects anticipation of the 'stress' of the waking phase. {{U}}(48) {{/U}} We made recordings of electroencephalogram, electrooculogram and electromyogram throughout the night, and took blood samples every 15 minutes to determine plasma concentrations of adrenocorticortropin and cortisol. Lights were turned off at midnight, after subjects had been told they would be woken at either 6:00 ('short sleep', on one night) or 9:00('long sleep', on the other two nights). On one of the long-sleep nights they were woken at 9:00 as they expected, but on the other night they were instead woken at 6:00 ('surprise')under the pretence of a technical problem. {{U}}(49) {{/U}} We interviewed the volunteers at the end of the experiments, and found that all but one of the subjects had expected to be woken up at the specified time. The order of the three experimental nights was balanced across subjects, with five subjects starting with short sleep, five with long sleep, and five with the surprise condition. The increase in adrenocorticotropin release before the expected time of waking indicates that anticipation, which is generally considered to be a unique characteristic of the regulation of conscious action, pervades sleep {{U}}(50) {{/U}} The regulation of adrenocorticotropin release points to a mechanism that quickly adjusts endocrine activity to sharp changes in the duration. A. The regulation of sleep termination has been thought to embedded in a daily rhythm controlling in paralleling the release of pituitary and adrenal hormones. B. Fifteen healthy volunteers with regular sleep-wake rhythms were studied during three nights. C. It also reflects a preparatory process in anticipation of the end of sleep D. After being woken, subjects stayed in bed for another three hours E. The anticipatory adrenocorticotropin increase may also facilitate spontaneous waking F. About 10 million Americans consult doctors sleep problems each year

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}}Can Loud Music Cause Hearing Impairment (损伤)?{{/B}} Have you ever gone to a concert and realized that your seats were right next to the booming speakers? Are you guilty______(51) turning up the volume on your portable cassette or CD player to drown out the whining (哭哭啼啼) of your little brother? Sometimes it's difficult to avoid loud music or noises, but they can be bad news because loud noises can______(52) temporary or permanent hearing loss. Extremely loud music and noises that go on for long periods of______(53) are common causes of deafness. If a noise is so loud that you have to shout to make yourself______(54), there is a______(55) that the mechanism inside your ear can be injured. Temporary hearing loss can happen after you've been______(56) to loud noise for only 15 minutes. If you have temporary hearing loss, you won't be able to hear as______(57) as you normally can, and you may have tinnitus (耳鸣), which is a fancy word for ringing in the ears. Your ears can feel "full", too.______(58), these things usually go away and your hearing soon returns to normal. Permanent hearing loss can happen when someone is exposed to loud noise ______(59) and over. Construction workers and people who work in factories must ______(60) ear protectors because the equipment they use can be extremely loud. But even some lawn mowers (割草机) and power tools can permanently______(61) a person's ability to hear high-pitched noises and can also give him permanent tinnitus. Listening to extremely loud music over and over can also have the same effect on a person's______(62). And using headphones on a portable cassette or CD player can be dangerous______(63) if the volume is too high and the headphones are used a lot, the noise can damage the ears. The best way to avoid hearing loss is to wear ear protectors when working with machinery and earplugs when going to a______(64). Headphones are OK to wear when you're listening to music; just be sure the volume isn't too high, and give them a rest______(65) once in a while.

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}} Eat for a Good and Healthful Life{{/B}} Food{{U}} (1) {{/U}}us alive. It is our sustenance and our pleasure. But recently, research has shown that the eating habits of the average Americans may be dangerous to future health. The foods Americans now choose are oftentimes too{{U}} (2) {{/U}}in calories and fats, so this article reports a new study: Diet and Health, Implications for Reducing Chronic Disease Risk. The study, conducted{{U}} (3) {{/U}}the National Research Council's Committee on Diet and Health,{{U}} (4) {{/U}}that balancing nutrition, calories and activity is key{{U}} (5) {{/U}}enjoying a long and healthful life. The report recommends that most Americans increase{{U}} (6) {{/U}}activity to a moderate level and make changes in food{{U}} (7) {{/U}}and calories intake to maintain ideal weight. Most of us-- even those of us at ideal weight--need to eat{{U}} (8) {{/U}}fat so that no more than 30% of our dally calories will come from fat. That means cutting{{U}} (9) {{/U}}on red meat and whole milk dairy products.{{U}} (10) {{/U}}, eat fish, chicken without skin, lean meats, and low-fat and no-fat dairy products. The report of the Committee on Diet and Health recommends we eat five or more 1/2-cup servings of vegetables and fruits{{U}} (11) {{/U}}-- especially green and yellow vegetables and citrus fruits. Eating more fruits and vegetables doesn't have to mean increased calories intake. Many plant foods are nutrient-rich: they provide many vitamins and minerals for very few{{U}} (12) {{/U}}. Nutrient-rich foods are particularly important for Americans{{U}} (13) {{/U}}age 50. As we{{U}} (14) {{/U}}, we need to eat less because our bodies need{{U}} (15) {{/U}}calories to function properly. But we still need full measures of vitamins and minerals to release the energy in our foods and make us feel strong and healthy.

语法与词汇John has always remained (loyal) to his family and friends.

语法与词汇Einstein''s theory of relativity seemed (incredible) when it was first introduced.