单选题You should use ______ language when you write a business letter.A. formalB. politicalC. magicD. plain

单选题Boil drinking water for at least five minutes, to kill the {{U}}germs{{/U}}, then let it cool in a clean container. Keep it covered.

单选题There are hardly any risks involved in cosmetic operations.

单选题The police contended that the difficulties they faced were too severe.

单选题As my train wasn't due to leave for another hour, I had plenty of time to spare. After buying some newspaper to read on the journey, I made my way to the luggage office to collect the heavy suitcase I had left there 3 clays before. There were only a few people waiting, and I took out my wallet to find the receipt for my case. The receipt didn't seem to be where l had left it. I emptied the contents of the wallet, and railway-tickets, money, scraps of paper, and photographs fell out of it; but no matter how hard I searched, the receipt was nowhere to be found. When my turn came, I explained the situation sorrowfully to the assistant. The man looked at me suspiciously as if to say that he had heard this type of story many times and asked me to describe the case. I told him that it was an old, brown-looking object no different from the many cases I could see on the shelves. The assistant then gave me a form and told me to make a list of the chief contents of the case. If they were correct, he said, I could take the case away. I tried to remember all the articles I has hurriedly packed and wrote them down as they came to me. After I had done this I went to look among the shelves. There were hundreds of cases there and fur one dreadful moment, it occurred to me that if someone had picked the receipt up, he could have easily claimed the case already. This hadn't happened fortunately, for after a while I found the case lying in a corner. After examining the articles inside, the assistant was soon satisfied that it was mine and told me I could take the case away. Again I took out my wallet: this time to pay. I pulled out a ten-shilling note and the "lost" receipt slipped out with it. I couldn't help blushing and looked up at the assistant, he was nodding his head knowingly, as if to say that he had often seen this hap pen before too.

单选题I seldom watch TV.

单选题Breastfeeding Can Cut Cardiovascular (心血管的) Risk Breastfeeding can reduce the risk of a heart attack or stroke later in life and could prevent hundreds of 1 of deaths each year, researchers said on Friday. Babies who are breastfed have fewer childhood infections and allergies (过敏) and are less 2 to obesity (肥胖). British scientists have now shown that breastfeeding and slow growth in the first weeks and months of life has a protective effect 3 cardiovascular disease. "Diets that promote more rapid growth put babies at risk many years later in 4 of raising their blood pressure, raising their cholesterol (胆固醇) and increasing their tendency to diabetes (糖尿病) and obesity—the 5 main risk factors for stroke and heart attack", said Professor Alan Lucas of the Institute of Child Health in London. "Our evidence suggests that the reason why breastfed babies do better is because they grow more 6 in the early weeks." Lucas said the effects of breastfeeding on blood pressure and cholesterol later in life are greater than 7 adults can do to control the risk factors for cardiovascular disease, other than taking drugs. An estimated 17 million people die of 8 disease, particularly heart attack and strokes each year, according to the World Health Organization. Lucas and his colleagues compared the health of 216 teenagers 9 as babies had either been breastfed or given different nutritional baby formulas. They reported their 10 in medical journal. The teenagers who had been 11 had a 14 percent lower ratio of bad to good cholesterol and lower concentrations of a protein that is a marker for cardiovascular disease risk. The researchers also found that 12 of the child"s weight at birth, the faster the infants grew in the early weeks and months of life, the 13 was their later risk of heart disease and stroke. The effect was the 14 for both boys and girls. "The more human milk you have in the new born period, the lower your cholesterol level is and the lower your blood pressure is 16 years 15 ," Lucas said.

单选题{{B}}第三篇{{/B}}{{B}}NewAttemptstoEradicateAIDSVirus{{/B}}Ahigh-profileattempttoeradicatetheAIDSvirusinafewpatientscontinuestoshowpromise.Butresearcherswon'tknowforayearormorewhetheritwillwork,scientistDavidHotoldjournalistshereWednesdayfortheFourthConferenceinVirusesandInfections."Thisisastudythat'sinprogress,"saysHo,headoftheAaronDiamondAIDSResearchCenter,NewYork.Thestudyinvolves20peoplewhostartedcombinationsofanti-HIVdrugsveryearlyinthecourseofthedisease,within90daysoftheirinfections.They'vebeentreatedforupto18months.Fourothershavedroppedoutbecauseofsideeffectsorproblemscomplyingwiththeexactingdrugsystem.ThedrugshaveknockedtheAIDSvirusdowntoundetectablelevelsinthebloodofallremainingpatients,sAnd,inthelatestdevelopment6,scientistshavenowtestedlymphnodesandsemenfromafewpatientsandfoundnovirusreproducingthere,Hosays."Bearinmindthat?undetectabledoesnotequalabsent,"Hosays.Hohascalculatedthatthedrugsshouldbeabletowipeoutremainingviruses--atleastfromknownreservoirsthroughoutthebody--intwotothreeyears.Buttheonlywaytoproveeradicationwouldbetostopthedrugsandseeiftheviruscomesback8.OnWednesday,Hosaidhewouldn'taskanypatienttoconsiderthatstepbefore2yearsoftreatment.Andheemphasizedthatheisnoturgingwidespreadadoptionofsuchearly,aggressivetreatmentoutsideoftrials9.Nooneknowsthelong-termrisks.Butotherscientistsarelookingatsimilarexperiments.Afederallyfundedstudywillput300patientsontriple-drugtreatmentsandthenseeifsomerespondingwellaftersixmonthscancontinuetosuppressthevirusonjustoneortwodrugs,saysresearcherDouglasRichmanoftheUniversityofCalifornia,SanDiego.Somepatientsinthatstudyalsomaybeofferedthechancetostoptherapyafter18monthsormore,hesays.

单选题The young man was so ______ and he always donates some money to those people in trouble.A. handsomeB. genuineC. talentedD. generous

单选题In 1976 more than 500 people contracted an autoimmune disease called Guillain - Barresyndrome after receiving swine - flu shots in response to a small outbreak in Fort Dix, N. J. Some people understandably fear a repeat of that tragic episode, However, vaccine, production techniques have changed since then. Today, vaccines are highly purified to eliminate any potential contaminants. In addition, scientists use only selected viral proteins in the shots, not the entire virus, as they did in the 1970s. "The public is comparing this vaccine to the 1976 swine--flu vaccine," says CDC spokesperson Abbigail Tumpey. "In fact, the best comparison is to the seasonal vaccines of the last ten years. " Nowadays ,vaccines are highly purified toA. remove people's fear for vaccine.B. avoid repeating the tragic episode in 1976.C. get rid of any possible contaminants.D. improve vaccine -production techniques.

单选题The secretary is expected to {{U}}explore{{/U}} ideas for post-war reconstruction of the area. A. deny B. investigate C. stress D. create

单选题For young children, getting dressed is a complicated business.

单选题It's almost impossible to find him in the {{U}}immense{{/U}} ocean. A.natural B.fatal C.tiny D.enormous

单选题Society is now much more Udiverse/U than ever before.

单选题Charges for local telephone calls are {{U}}outrageous{{/U}}. A.unheard of B.unacceptable C.unbelievable D.ridiculous

单选题It is virtually impossible to persuade him to apply for the job.

单选题Our arrangements were thrown into complete turmoil .

单选题 下面有3篇短文，每篇短文后有5道题，每道题后面有4个选项。请仔细阅读短文并根据短文内容回答其后面的问题，从4个选项中选择1个最佳答案。{{B}}第一篇{{/B}} {{B}} Early or Later Day Care{{/B}} The British psychoanalyst John Bowlby maintains that separation from the parents during the sensitive "attachment" period from birth to three may scar a child's personality and predispose to emotional problems in later life. Some people have drawn the conclusion from Bowlby's work that children should not be subjected to day care before the age of three because of the parental separation it entails, and many people do believe this. But there are also arguments against such a strong conclusion. Firstly, anthropologists point out that the insulated love affair between children and parents found in modem societies does not usually exist in traditional societies. For example, in some tribal societies, such as the Ngoni, the father and mother of a child did not rear their infant alone--far from it. Secondly, common sense tells us that day care would not be so widespread today if parents, care-takers found children had problems with it. Statistical studies of this kind have not yet been carded out, and even if they were, the results would be certain to be complicated and controversial. Thirdly, in the last decade there have been a number of careful American studies of children in day care, and they have uniformly reported that day care had a neutral or slightly positive effect on children's development. But tests that have had to be used to measure this development are not widely enough accepted to settle the issue. But Bowlby's analysis raises the possibility that early day care has delayed effects. The possibility that such care might lead to, say, more mental illness or crime 15 or 20 years later can only be explored by the use of statistics. Whatever the long-term effects, parents sometimes find the immediate effects difficult to deal with. Children under three are likely to protest at leaving their parents and show unhappiness. At the age of three or three and a half almost all children find the transition to nursery easy, and this is undoubtedly why more and more parents make use of child care at this time. The matter, then, is far from clear-cut, though experience and available evidence indicate that early care is reasonable for infants.

单选题Liver Disease The liver is the second largest organ in your body. The liver performs many jobs in your body. It processes what you eat and drink into energy and nutrients your body can use. The liver also removes harmful substances from your blood. One out of every 10 Americans is affected by liver disease. Liver disease is one of the top 10 causes of death in the United States. There are more than 100 liver diseases. Viruses cause some of them, like hepatitis A, hepatitis B and hepatitis C. Others can be the result of drugs, poisons or drinking too much alcohol. If the liver forms scar tissue because of an illness, it"s called cirrhosis. Cancer can affect the liver. You should also inherit a liver disease such as hemochromatosis. Liver disease can manifest in many ways. Characteristic manifestations include jaundice, liver enlargement, portal hypertension and etc. Sometimes the manifestations of liver disease are not obvious. For example, symptoms may include fatigue, a general feeling of illness, loss of appetite, and mild weight loss. However, people may not notice these symptoms, and these symptoms are also typical of many other diseases. Thus, liver disease can easily be overlooked, particularly in its early stages. Hepatitis A vaccination is the best way to prevent HAV (hepatitis A virus). Hepatitis B vaccination is the best way to prevent HBV. Other ways to stop the spread of HBV are: not sharing needles; practicing safe sex; not Sharing razors, toothbrushes, or other personal items; using only clean needles for fattoos and body piercings. There is no vaccine to prevent HCV. The only way to prevent HCV is to avoid direct contact with infected blood. Eating a healthy diet and exercising regularly help the liver to work well. Limit the amount of alcohol you drink. When medicines are taken incorrectly, the liver can be harmed. So follow dosing instructions and talk to a doctor or pharmacist about the medicines you are taking. Mixing alcohol and medicines can harm your liver, even if they are not taken at the same time. Toxins can injure liver cells. So limit direct contact with toxins from cleaning and aerosol products, insecticides, chemicals, and additives in cigarettes. Do not smoke.

单选题Medicine Award Kicks off Nobel Prize Announcements Two scientists who have won praise for research into the growth of cancer cells could be candidates for the Nobel Prize in medicine when the 2008 winners are presented on Monday, kicking off six days Nobel announcements. Australian-born U. S. citizen Elizabeth Blackburn and American Carol Greider have already won a series of medical honors for their enzyme research and experts say they could be among the front-runners for Nobel. Only seven women have won the medicine prize since the first Nobel Prizes were handed out in 1901. The last female winner was U.S. researcher Linda Buck in 2004, who shared the prize with Richard Axel. Among the pair"s possible rivals are Frenchman Pierre Chambon and Americans Ronald Evans and Elwood Jensen, who opened up the field of studying proteins called nuclear hormone receptors. As usual, the award committee is giving no hints about who is in the running before presenting its decision in a news conference at Stockholm"s Karolinska Institute. Alfred Nobel, the Swede who invented dynamite, established the prizes in his will in the categories of medicine, physics, chemistry, literature and peace. The economics prize is technically not a Nobel but a 1968 creation of Sweden"s central bank. Nobel left few instructions on how to select winners, but medicine winners are typically awarded for a specific breakthrough rather than a body of research. Hans Jornvall, secretary of the medicine prize committee, said the 10 million kronor (US $1.3 million) prize encourages groundbreaking research hut he did not think winning it was the primary goal for scientists. "Individual researchers probably don"t look at themselves as potential Nobel Prize winners when they"re at work," Jornvall told The Associated Press. "They get their kicks from their research and their interest in how life functions." In 2006, Blackburn, of the University of California, San Francisco, and Greider, of Johns Hopkins University in Baltimore, shared the Lasker prize for basic medical research with Jack Szostak of Harvard Medical School. Their work set the stage for research suggesting that cancer cells use telomerase to sustain their uncontrolled growth.