单选题This kind of animals are on the verge of extinction, because so many are being killed for their fur. A. drying up B. dying out C. being exported D. being transplanted

单选题Pure feldspar is a colorless, transparent mineral, but impurities commonly make it opaque and colorful.______

单选题 Scientists Develop Ways of Detecting Heart Attack German researchers have (1) a new generation of defibrillators and early warning software aimed at offering heart patients greater protection (2) sudden death from cardiac arrest. In Germany alone around 100,000 people die annually as a result of cardiac arrest and many of these cases (3) by disruption to the heart's rhythm. Those most at risk are Patients who have (4) suffered a heart attack and for years the use of defibrillators has proved useful in diagnosing (5) disruptions to heart rhythms and correcting them automatically by intervening within seconds. These devices (6) a range of functions such as that of pacemaker. Heart specialists at Freiburg's University Clinic have now achieved a breakthrough with all implanted defibrillator (7) of generating a six-channel electrocardiogram(ECG) within the body. This integrated system allows early diagnosis of (8) blood-flow problems and a pending heart attack. It will be implanted in patients for the first time this year. Meanwhile, researchers at the Fraunhofer Institute for Applied Mathematics in Kaiserslautern have developed new computer software that renders the evaluation of ECG data (9) . The overwhelming (10) of patients at risk will not have an implanted defibrillator and must for this reason undergo regular ECGs. "Many of the current programs only (11) into account a linear correlation of the data. We are, however, making use (12) a non-linear process that reveals the chaotic patterns of heart beats as an open and complex system." Hagen Knaf says." (13) changes in the heart beats over time can be monitored and individual variations in patients taken into account." An old study of ECG data, based (14) 600 Patients who had suffered a subsequent heart attack, enabled the researchers to compare risks and to show (15) the new software evaluates the data considerably better.

单选题Writing is a slow process,requiring {{U}}plenty of{{/U}} thought, time and effort。

单选题Their talents are not only enormous but durable.A. elasticB. lastingC. flexibleD. suitable

单选题 Is Your Child's Stomach Pain All in His Head? We all know there are times that kids seem to complain {{U}} {{U}} 1 {{/U}} {{/U}}a stomachache to get out of chores or going to school. Don't be so sure that the pain they {{U}} {{U}} 2 {{/U}} {{/U}}is all in their minds. We're learning more now about a condition {{U}} {{U}} 3 {{/U}} {{/U}}"functional abdominal pain" that is experienced by millions of kids every day. Like many teenagers, Kyle Brust makes it a point to do his homework as {{U}} {{U}} 4 {{/U}} {{/U}}as he gets home. Unlike most, Kyle often did this with a terrible stomachache. In fact, the {{U}} {{U}} 5 {{/U}} {{/U}}often started while he was at school, but getting help there was getting harder. "Some of my teachers wouldn't let me go, because I'd asked so many times before and they thought I was trying to get out of {{U}} {{U}} 6 {{/U}} {{/U}}," says Kyle. Kyle's mom Marilyn says she couldn't blame the {{U}} {{U}} 7 {{/U}} {{/U}}. After all, she'd taken him to the doctor several times herself, and even they couldn't find anything {{U}} {{U}} 8 {{/U}} {{/U}}. "You know, you're running the tests and nothing's coming up. So, is it in his head, is he just an extremely stressful child? It's just frustrating {{U}} {{U}} 9 {{/U}} {{/U}}we're not finding any answers," says Marilyn. It turns out Kyle was suffering from a condition known {{U}} {{U}} 10 {{/U}} {{/U}}functional abdominal pain, that affects as many as one out of every ten kids in this country. Even {{U}} {{U}} 11 {{/U}} {{/U}}the cause of the pain may not be obvious, there are real consequences. "It really does hurt, and these kids really do suffer," says Dr. Campo, MD at Nationwide Children's Hospital. To help {{U}} {{U}} 12 {{/U}} {{/U}}, Campo is looking into a new approach. He's conducting clinical trials of an antidepressant that changes the way the body handles a chemical called serotonin. In a preliminary study, Dr. Campo found that in about eight out of ten {{U}} {{U}} 13 {{/U}} {{/U}}, the drug normally used to treat emotional pain worked to ease the pain in the {{U}} {{U}} 14 {{/U}} {{/U}}. "We think about it as being important in anxiety and depression and that's all quite true, but what's really interesting is that 95% of our body's serotonin is in our gut," says Campo. Campo believes these kids have extremely sensitive intestines, and controlling the effects of serotonin may {{U}} {{U}} 15 {{/U}} {{/U}}ease the pain. It seemed to work for Kyle, who is now completely pain free for the first time in years.

单选题{{U}}Subterranean{{/U}} streams have cut through limestone to form miles of passages and caves such as Kentucky's Mammoth Cave.

单选题The movie has a {{U}}satisfying{{/U}} ending. A.pleasing B.sad C.interesting D.horrific

单选题 Look After Your Voice Often speakers at a meeting experience dry mouths and ask for a glass of water. You can solve the problem by activating the saliva in you mouth. First gently bite the edges of your tongue with your teeth. Or, press your entire tongue to the bottom of your mouth and hold it there until the saliva flow. Or you can imagine that you are slicing a big juicy lemon and sucking the juice. Before you begin your talk, be kind to your voice. Avoid milk or creamy drinks which coat your throat. Keen your throat wet by drinking a little sweetened warm tea or diluted fruit juice. If you sense that you are losing your voice, stop talking completely. Save your voice for your speech. You may feel foolish using paper to write notes, but the best thing you can do is to rest your voice. If you need to see a doctor, perhaps you can get some advice from a professional singer. In the meantime, do not even talk in a low voice. What about drinking alcohol to wet your throat? I advice you not to touch alcohol before speaking. The problem with alcohol is that one drink gives you a little confidence. The second drink gives you even more confidence. Finally you will feel all-powerful and you will feel you can do everything, but in fact your brain and your mouth do not work together properly. Save the alcohol until you finish speaking. Perhaps you want to accept the advice, but you may wonder if you can ever change the habits of a lifetime. Of course you can. Goethe, who lived before indoor skating rinks or swimming pools, said, "We learn to skate in the summer and swim in the winter." Take this message to heart and give yourself time to develop your new habits. If you are willing to change, you will soon be able to say that you will never forget these techniques because they became a part of your body.

单选题{{U}}Alternative{{/U}} sources of protein must be found when meat and fish are not available.

单选题It was obvious that she was not going home.

单选题I think you were {{U}}wise {{/U}}to leave when you did.

单选题He talks tough but has a tender heart.

单选题{{B}}第三篇{{/B}} American society is not nap(午睡)friendly. In fact, says David Dinges, a sleep specialist at the University of Pennsylvania School of Medicine. "There's even a prohibition against admitting we need sleep". Nobody wants to be caught napping or found asleep at work. To quote a proverb: "Some sleep five hours, nature requires seven, laziness nine and wickedness eleven~" Wrong. The way not to fall asleep at work is to take naps when you need them. "we have to totally change our attitude toward napping", says Dr. William Dement of Stanford University, the godfather of sleep research. Last year a national commission led by Dement identified an "American sleep debt" which one member said was a important as the national debt. The commission was concerned about the dangers of sleepiness people causing industrial accidents of failing asleep while driving. This may be why we have a new sleep policy in the Whiter House. According to recent reports, president Clinton is trying to take a half-hour snooze(打瞌睡 )every afternoon. About 60 percent of American adults nap when given the opportunity. We seem to have "a mid-afternoon quiet phase" also called "a secondary sleep gate." Sleeping 15 minutes to two hours in the early afternoon can reduce stress and make us refreshed. Clearly, we were born to nap. We Superstars of snooze don't nap to replace lost shuteye or to prepare for a night shift. Rather, we "snack" on sleep, whenever, wherever and at whatever time we feel like it. I myself have napped in buses, cars, planes and on boats; on floors and beds and in libraries, offices and museums.

单选题They agreed to settle the dispute by peaceful means.

单选题Phil Harris was {{U}}hurtled{{/U}} into the business world at an age when most of today's teenagers are battling with "0" levels.

单选题The effect of higher oil prices has been substantially offset by the recent yen appreciation.A. representedB. increasedC. cancelled outD. paid

单选题Earth Rocks On Most of the time, the ground feels solid beneath our feet. That"s comforting. But it"s also misleading because there"s actually a lot going on underground. Masses of land (called plates) slip, slide, and bump against each other, slowly changing the shape of continents and oceans over millions and billions of years. Scientists know that Earth formed about 4.5 billion years ago. They also know that our planet was hot at first. As it cooled, its outermost layer, called the crust (地壳), eventually formed moving plates. Exactly when this shift happened, however, is an open question. Now, an international group of researchers has an answer. They"ve found new evidence suggesting that Earth"s crust started shifting at least 3.8 billion years ago. The new estimate is 1.3 billion years earlier than previous ones. Not long before 3.8 billion years ago, lots of asteroids (小行星) were hitting Earth, keeping its crust in a hot, melted state. After the hard crust formed, much of it sank at various times into the planet"s hot insides. There, it melted before returning to the surface. In some places, however, the crust never sank. One of the oldest such places is in Greenland, in an area called the Isua supracrustal (上地壳) belt. The rocky crust there is between 3.7 and 3.8 billion years old. The belt was once part of the seafloor, but now it is exposed to air. The researchers recently took a close look at the Isua supracrustal belt. They noticed long, parallel cracks in the rock that have been filled in with a type of volcanic rock. To explain this structure, the scientists propose that tension in the crust caused the seafloor to crack open long ago. Hot, liquid rock, called magma (岩浆), flowed up slowly from deep inside Earth to fill the cracks. Finally, the whole area cooled, forming what we see today. That explanation, plus chemical clues inside the rock, suggests that the Isua supracrustal belt was once part of a plate under the ocean, beginning around 3.8 billion years ago.

单选题I'm glad I'm not in his shoes with all those debts to pay off. A. in his office B. in his car C. in his position D. his friend

单选题Step Back in Time Do you know that we live a lot longer now than the people who were born before us? One hundred years ago the average woman lived to be 45. But now, she can live until at least 80. One of the main reasons for people living longer is that we know how to look after ourselves better. We know which foods are good for U.S. and what we have to eat to make sure our bodies get all the healthy things they need. We know why we sometimes get ill and what to do to get better again. And we know how important it is to do lots of exercise to keep our hearts beating healthily. But in order that we don't slip back into bad habits, let's have a look at what life was like 100 years ago. Families had between 15 and 20 children, although many babies didn't live long. Children suffered from lots of diseases, especially rickets (佝偻病) and scurvy (坏血病), which are both caused by bad diets. This is because many families were very poor and not able to feed their children well. Really poor families who lived in crowded cities like London and Manchester often slept standing up, bending over a piece of string, because there was no room for them to lie down. People didn't have fridges until the 1920s. They kept fresh food cold by storing it on windowsills (窗台板) , blocks of ice, or even burying it in the garden. Some children had to start work at the age of seven or eight to earn money for their parents. If you had lived 100 years ago, you might well be selling matchsticks (火柴杆) (a job done by many children) or working with your dad by now.