单选题The girl is gazing at herself in the mirror.

单选题The use of the chemical may present a certain hazard to the laboratory workers.

单选题I have heard this tune before, but I don't know the words to the song.A. themeB. rhymeC. melodyD. lyric

单选题Late-Night Drinking Coffee lovers beware. Having a quick "pick-me-up" cup of coffee late in the day will play havoc with your sleep. As well as being a stimulant, caffeine interrupts the flow of melatonin, the brain hormone that sends people into a sleep. Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 2 a.m. and 4 a.m., before falling again. "It"s the neurohormone that controls our sleep and tells our body when to sleep and when to wake," says Manrice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body"s levels of this sleep hormone. Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decal. On average, subjects slept 336 minutes per night after drinking caffeinated coffee, compared with 415 minutes after decal. They also took half an hour to drop off—twice as long as usual—and jigged around in twice as much. In the second phase of the experiment, the researchers woke the volunteers every three hours and asked them to give a urine sample. Shilo measured concentrations of a breakdown product of melatonin. The results suggest that melatonin concentrations in caffeine drinkers were half those in decal drinkers. In a paper accepted for publication in Sleep Medicine , the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production. Because it can take many hours to eliminate caffeine from the body, Ohayon recommends that coffee lovers switch to decal after lunch.

单选题The Case of the Disappearing Fingerprints One useful anti-cancer drug can effectively erase the whorls and other characteristic marks that give people their distinctive fingerprints. Losing 1 could become troublesome. A case released online in a letter by Annals of Oncology indicates bow big a 2 of losing fingerprints is. Eng-Huat Tan, a Singapore-based medical doctor describes a 62-year old man who has used capecitabine to 3 his nasopharyngeal cancer. After three years on the 4 , the patient decided to visit U.S. relatives last December. But be was stopped by U. S. customs officials 5 4 hours after entering the country when those officials couldn"t get fingerprints from the man. There were no distinctive swirly 6 appearing from his index finger. U.S. customs has been fingerprinting incoming foreign visitors for years, Tan says. Their index fingers are 7 and screened against digital files of the fingerprints of bad guys—terrorists and potential criminals that our federal guardians have been tasked with keeping out of the country. Unfortunately, for the Singaporean travelers, one potential 8 effect of his drug treatment is a smoothing of the tissue on the finger pads. 9 , no fingerprints. "It is uncertain when fingerprint loss will 10 to take place in patients who are taking capecitabine," Tan points out. So he cautions any physicians who 11 the drug to provide their patients with a doctor"s note pointing out that their medicine may cause fingerprints to disappear. Eventually, the Singapore traveler made it into the United States. I guess the name on his passport didn"t raise any red flags. But he"s also now got the explanatory doctor"s note—and won"t leave home 12 it. By the way, maybe the Food and Drug Administration, 13 approved use of the drug 11 years ago, should consider 14 its list of side effects associated with this medicine. The current list does note that patients may experience vomiting, stomach pain and some other side effects. But no where 15 it mention the potential for loss of fingerprints.

单选题The food is inadequate for ten people.

单选题Continuous short buzzes on the telephone indicate that the line is Ubusy/U after you dial the telephone number.

单选题"Wash every day and you'll die young, my son!" People often said those words; long ago, of course. Napoleon's wife had new clothes every month, instead of a bath. ("It's quicker," She always said). Rich people did not often have a bath. They washed their hands and faces, but not their bodies. Many poor people did not wash at all. A young man once said to a doctor; "Soap and water have never touched my body." (And the doctor answered. "That's true. I know... ") why didn't people wash in those days long ago? Well, they did not have water in their house. They carried water from rivers or from holes in the ground ( = wells). Towns people bought it from a water--carrier. Sometimes it was expensive; and soap was always expensive. They drank water, of course; and so they were clean inside. They did not think about the outside! And this is true; they just did not like a bath. Modern life is different. We use a lot of soap and water. And we are all quite clean. However, a few people use too much soap; and they often get ill. Who are these people? Many young women work as hairdressers. They wash and then "dress" other women's hair. That is their job, and they like it. Young hairdressers sometimes wash dirty heads on a busy day! Their hands are soapy for seven or eight hours; and that is not a good thing. A young hairdresser's hands are often red and ugly; and she must then go to doctor.

单选题A co - worker of mine recently recommended to do some research online before making my next purchase. As an elementary school teacher with a modest salary and a sizeable mortgage, cost was a major concern. While searching the Web I found a few online teeth whitening companies giving away free trials where you only had to pay a few dollars for shipping. I ordered two products, Dazzle White and Total White, both of which had 9/10 ratings and positive feedback from all users. After using the first product the results were noticeable, but after following with the second product I had a celebrity white smile. I'm far from a medical expert, but it appears that each product focused on DIFFERENT parts of the problem and that the second one put the whitening effect into overdrive. By using them both in a row I had absolutely unbelievable results. I can't believe companies are practically giving these products away! What is the economic status of the elementary school teacher?A. A not big salary with a great mortgage.B. Avery small salary to buy anything fancy.C. A not big salary with a moderate mortgage.D. A good salary with a great mortgag

单选题The unemployment rate may rise {{U}}slightly{{/U}}.

单选题Older Volcanic Eruptions Volcanoes were more destructive in ancient history, not because they were bigger, but because the carbon dioxide they released wiped out life with greater ease. Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off large numbers of animals, but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock. To his surprise, the older the massive volcanic eruptions were, the more damage they seemed to do. He calculated the "killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava that they produced. He found that size for size, older eruptions were at least 10 times as effective at wiping out life as their more recent rivals. The Permian extinction, for example, which happened 250 million years ago, is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe. Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide. The global warming that followed wiped out 80 percent of all marine genera at the time, and it took 5 million years for the planet to recover. Yet 60 million years ago, there was another huge amount of volcanic activity and global warming but no mass extinction. Some animals did disappear but things returned to normal within ten thousands of years. "The most recent ones hardly have an effect at all," Wignall says. He ignored the extinction which wiped out the dinosaurs 65 million years ago, because many scientists believe it was primarily caused by the impact of an asteroid. He thinks that older volcanoes had more killing power—because more recent life forms were better adapted to dealing with increased levels of CO 2 . Vincent Courtillot, director of the Paris Geophysical Institute in France, says that Wignall"s idea is provocative. But he says it is incredibly hard to do these sorts of calculations. He points out that the killing power of volcanic eruptions depends on how long they lasted. And it is impossible to tell whether the huge blasts lasted for thousands or millions of years. He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced, and that lava volume may not necessarily correspond to carbon dioxide emissions.

单选题Some people would like to do shopping on Sundays since they expect to pick up wonderful articles in the market.

单选题He appeared to be talking to himself.A. seemedB. lovedC. preferredD. used

单选题The older I get, the younger I want to look. As a woman who has never believed in wearing makeup. I always assumed I would age gracefully and be happy about it. But that plan, which sounded so infallible (永远正确的) at age 20, doesn't seem quite as appealing now that I'm pushing 40 and gravity is beginning to win the war. In the writer's eyes, aging gracefullyA. is an infallible ideaB. is not an appealing ideaC. can make her happyD. is something worth respect

单选题This is not typical of English, but is a feature of the Chinese language.

单选题I catch a cold now and then .______

单选题Keep on Fighting Turning once again to the question of invasion, I would observe that there has never been a period in all these long centuries of which we boast when an absolute guarantee against invasion, still less against serious raids, could have been given to our people. In the davs of Napoleon the same wind which would have carried his transports across the Channel might have driven away the blockading (封锁) fleet. There was always the chance, and it is that chance which has excited and befooled (愚弄) the imaginations of manv continental tyrants. Many are the tales that are told. We are assured that novel methods will be adopted, and when we see the originality of malice (怨恨), the ingenuity of aggression, which our enemy displays, we may certainly prepare ourselves for every kind of novel stratagem (战略) and every kind of brutal and treacherous (奸诈的) maneuver (花招). I think that no idea is so outlandish (古怪的) that it should not be considered and viewed with a searching, but at the same time, I hope，with a steady eye. We must never forget the solid assurances of sea power and those which belong to air power if it can be locally exercised. At any rate, that is what we are going to try to do. This is the resolve of His Majesty"s government—every man of them. This is the will of parliament and the nation. The British Empire and the French republic, linked together in their cause and in their need, will defend to the death their native soil, aiding each other like good comrades to the utmost of their strength. Even though large tracts of Europe and many old and famous states have fallen or may fall into the grip of the Gestapo and all the odious (可憎的) apparatus of Nazi rule, we shall not flag (变弱) or fail. We shall go on to the end, we shall fight in France, we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air, we shall defend our island, whatever the cost might be, we shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills, we shall never surrender, and even if, which I do not for a moment believe, this island or a large part of it were subjugated (征服) and starving，then our empire beyond the seas, armed and guarded by the British fleet, would carry on the struggle, until, in God"s good time, the new world, with its power and might, steps forth to the rescue and the liberation of the old.

单选题 Cosmetic Surgery Surgery that can improve the way a person looks is becoming more and more popular in the United States. This kind of surgery is called cosmetic surgery, and both men and women are turning to this treatment as a way of keeping their appearance young as well as keeping competitive (有竞争力的) in their jobs. Men especially are beginning to turn to face-lifts (面部拉皮手术), liposuction (taking fat out of the body), and implants (putting artificial parts into their bodies) to help them look younger. As companies downsize (编造) and move younger employees into higher positions, older employees in their late forties and early fifties feel the need to look and act younger in order to stay competitive. These operations are not without dangers, however. One young woman had an eye operation to get rid of the bags under her eyes. She described her experience as terrible. She said, "When he started cutting, I was fully awake. Even though he'd given me an injection near my eyes, I saw everything." She went on to explain, "I knew I had to keep still because of what he was doing. He was scraping (刮) away fat underneath my eyes. It took about ten minutes. After he finished, I felt I couldn't walk. I was so faint." Her troubles did not end after the operation for two weeks. Her eyes were swollen (肿胀的) and almost completely closed, and even dark glasses could not hide the side effects of the operation. Liposuction, taking fat out of the body, is probably the most popular cosmetic operation in the United States. It seems simple enough. First, a small cut is made over the place where the patient wants the fat removed. Next, a small pipe is put into the cut. A machine like a vacuum cleaner is then used to suck the fat out of the body. However, as one doctor explained, some problems call happen after the operation. He warned, "Irregular lumps and loose skin can reset from this operation. If it is not evenly done, liposuction can produce a very lumpy result." Patients often must have more liposuction to correct the problem.

单选题Many cities have restricted smoking in public places.

单选题You'll be agreeably surprised by its reasonable price.A. cheapB. expensiveC. standardizedD. same