单选题Enamel, the hardest substance in a human being’s body, covers the {{U}}entire{{/U}} crown of the tooth.

单选题Sometimes it is advisable to book hotels in advance .

单选题 阅读下面这篇短文，短文后列出7个句子，请根据短文的内容对每个句子做出判断。 {{B}}How to Determine a Topic for Research{{/B}} Because you are going to put a lot of your time and energy into your research project(项目) ,the topic is especially important. In many instances your instructor may give a specific(特殊的)topic. I[ this is done, you have little choice, but most instructors will permit or even welcome a slightly changed focus(中心)in a topic if it is supported by good thinking. In some of your classes, the instructor may present a suggested list of several topics from which you are to make a choice. If this is done, do not simply select the first idea that attracts your attention. It may be one with which you will soon become bored, or it may be one on which you would have difficulty finding all the necessary information. Looking at the topics, try to consider how you might go about developing each of them. When you find out what seems especially interesting and worthwhile(值行骄傲的), do a bit checking in the library to see if you can get the basic resources you will need. Choosing a good research topic does not necessarily mean finding something that has a lot written about it. Many times you will have to research around a topic in order to find out the most useful information. Exciting and original topics often come to mind by combining two completely different interests. Let us say that you are interested in child psychology (心理学的)and in sports. Perhaps you can combine these into a study of the effect that is watching(可得到的)on the subject, you can research the topic individually and, by putting your information together, then draw a conclusion.

单选题Children model themselves largely on their parents. They do so mainly through identification. Children identify (51) a parent when they believe they have the qualities and feelings that are (52) of that parent. The things parents do and say-and the (53) they do and say to them—strongly influence a child's (54) . However, parents must consistently behave like the type of person they want their child to become. A parent's actions (55) affect the self image that a child forms (56) identification. Children who see mainly positive qualities in their (57) will likely learn to see themselves in a positive way. Children who observe chiefly negative qualities in their parents will have difficulty (58) positive qualities in themselves. Children may modify their self image, however, as they become increasingly (59) by peers groups standards. Isolated events, dramatic ones, do not necessarily have a permanent (60) on a child's behavior. Children interpret such events according to their established anitudes and previous training. Children who know they are loved can, for example, accept the divorce of their parents or a parent's early (61) . But if children feel unloved ,they may interpret such events (62) a sign of rejection or punishment. In the same way, all children are not influenced (63) by toys and games, reading matter, and television programs. (64) in the ease of a dramatic change in family relations, the (65) of an activity or experience depends on how the child interprets it.

单选题All the flats in the building had the same Ulayout/U.

单选题She was Uunwilling/U to go but she had no choice.

单选题He is certain that the dictionary is just what I want.

单选题Please give my best wishes to your family.

单选题{{B}}第三篇{{/B}} {{B}} Learning Disabilities{{/B}} Learning disabilities are very common. They affect perhaps 10 percent of all children. Four times as many boys as girls have learning disabilities. Since about 1970, new research has helped brain scientists understand these problems better. Scientists now know there are many different kinds of learning disabilities and that they are caused by many different things. There is no longer any question that all learning disabilities result from differences in the way the brain is organized. You cannot look at a child and tell if he or she has a learning disability. There is no outward sign of the disorder. So some researchers began looking at the brain itself to learn what might be wrong. In one study, researchers examined the brain of a learning-disabled person who had died in an accident. They found two unusual things. One involved cells in the left side of the brain, which control language. These cells normally are white. In the learning disabled person, however, these cells were gray. The researchers also found that many of the nerve cells were not in a line the way they should have been. The nerve cells were mixed together. The study was carried out under the guidance of Norman Geschwind, an early expert on learning disabilities. Doctor Gesehwind proposed that learning disabilities resulted mainly from problems in the left side of the brain. He believed this side of the brain failed to develop normally. Probably, he said, nerve cells there did not connect as they should. So the brain was like an electrical device in which the wires were crossed. Other researchers did not examine brain tissue. Instead, they measured the brain’s electrical activity and made a map of the electrical signals. Frank Duffy experimented with this technique at Children’s Hospital Medical Center in Boston. Doctor Duffy found large differences in the brain activity of normal children and those with reading problems. The differences appeared throughout the brain. Doctor Duffy said his research is evidence that disabilities involve damage to a wide area of the brain, not just the left side.

单选题下面的短文后列出了7个句子，请根据短文的内容对每个句子做出判断：如果该句提的是正确信息，请选择A：如果该句提的是错误信息，请选择B：如果该句的信息文中没有提及，请选择C。 Magaplane (巨型飞机) The Boeing Corp. and Europe's Airbus consortium (财团) are preparing to offer bigger airplanes to the world's airlines. Now that talks on a joint project have broken down, Boeing is pushing a stretched (拓展的) version of 747, and Airbus is designing an all-new aircraft, known as the A3XX. Seating 550 passengers in the basic model, and 650 in a stretched version, the 1. 2 million pound A3XX will not only be the largest airplane in the world, but it will also be one of the most advanceD. The outer wings and the horizontal stabilizer (as big as a smaller jet's wing) will be made of carbon-fiber composite materials, and will be the largest? such structures on any aircraft except the B-2 stealth bomber (隐形轰炸机). Metal skins will be welded (焊接) together with lasers, removing thousands of fasteners. When a strong wind strikes the A3XX's 260-foot wing, movable control surfaces will prevent it from flexing (扭曲) like a giant spring. This will make the ride smoother and will save weight by reducing the load on the wing spars (翼梁). A flexible-skinned flap (副翼) will subtly change the wing's curvature (曲面) to match the airplane's changing weight as it burns fuel on each journey. The A3XX will carry up to 1,600 meals, filling more than 100 food and beverage (饮料) carts. To make more room for passengers, Airbus plans to put the carts in the lower hold; automatic conveyors and elevators will deliver them to the two passenger decks. Airlines have asked Airbus to look at extra features ranging from lower-deck sleeper cabins to a children's playroom. Airbus expects to offer the A3XX to airlines in 1998, and deliver the first aircraft in 2003.

单选题{{B}}第三篇{{/B}} The Greatest Show on Earth The Olympic Games (奥林匹克运动会) are the greatest festival of sport in the world. Every four years, a hundred or more countries send their best sportsmen to compete (竞赛) for the highest honors in sport. As many as 6,000 people take part in over 20 sports. For the winners, there are gold medals(奖牌) and glory. But there is honor, too, for all who compete, win or lose. That is in spirit of the Olympics-to take part is what matters. The Olympic Games always start in a bright color and action. The teams of all the nations parade in the opening ceremony(仪式) and march round the track. The custom is for the Greek team to march in first. For it was in Greece that the Olympics began. The team of the country where the Games are being held-the host country-marches in last. The runner with the Olympic torch (火炬) then enters the stadium(体育场) and lights the flame. A sportsman from the host country takes the Olympic oath (誓言) on behalf of all the competitors(竞赛者). The judges and officials also take an oath. After the sportsmen march out of the stadium the host country puts on a wonderful display. The competitions begin the next day. There are usually more than twenty sports in the Games. The rule is that there must be at least fifteen. The main events are in track and field (田径) , but it is a few days before these sports start. Each day the competitors take part in a different sport-riding, shooting, swimming, and cross-country running. Points are gained for each event. Medals are awarded (颁发) for the individual winners and for national teams. More and more women are taking part in the games. They first competed in 1900, in tennis and golf, which are no longer held in the Oiympics. Women's swimming events were introduced in 1912. But it was not until 1928 that there were any track and field events for women. Now, they compete in all but half a dozen of the sports. In horse riding, shooting, and boat racing, they may compete in the same events as the men.

单选题阅读下面这篇短文，短文后列出了7个句子，请根据短文的内容对每个句子作出判断。如果该句提供的是正确信息，请选择A项；如果该句提供的是错误信息，请选择B项；如果该句的信息文章中没有提及，请选择C项。 {{B}}Magaplane (巨型飞机){{/B}} The Boeing Corp. and Europe's Airbus consortium (财团) are preparing to offer bigger airplanes to the world's airlines. Now that talks on a joint project have broken down, Boeing is pushing a stretched (拓展的) version of 747, and Airbus is designing an all-new aircraft, known as the A3XX. Seating 550 passengers in the basic model, and 650 in a stretched version, the 1.2 million pound A3XX will not only be the largest airplane in the world, but it will also be one of the most advanced. The outer wings and the horizontal stabilizer (as big as a smaller jet's wing) will be made of carbon-fiber composite materials, and will be the largest such structures on any aircraft except the B-2 stealth bomber (隐形轰炸机). Metal skins will be welded (焊接) together with lasers, removing thousands of fasteners. When a strong wind strikes the A3XX's 260-foot wing, movable control surfaces will prevent it from flexing (扭曲) like a giant spring. This will make the ride smoother and will save weight by reducing the load on the wing spars (翼梁). A flexible-skinned flap (副翼) will subtly change the wing's curvature (曲面) to match the airplane's changing weight as it burns fuel on each journey. The A3XX will carry up to 1,600 meals, filling more than 100 food and beverage (饮料) carts. To make more room for passengers, Airbus plans to put the carts in the lower hold; automatic conveyors and elevators will deliver them to the two passenger decks. Airlines have asked Airbus to look at extra features ranging from lower-deck sleeper cabins to a children's playroom.

单选题Many of Europe"s airports are heavily congested .

单选题 下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文并根据短文回答其后面的问题，从4个选项中选择1个最佳答案。{{B}}第一篇{{/B}} {{B}} Escaping from the Earth{{/B}} The Earth has a force that pulls things toward itself. We call this force gravity(地心引力). This is something we live with all the time, and we take it for granted and hardly ever think about it. But it is a most important factor in rocket operation and must be overcome if we are to get anywhere in space, or off the ground at all. Take the throwing of a hall as an example. The harder the ball is thrown, the faster and higher it will go. What is the secret? Its speed. If we could throw the ball hard enough it would go up and up forever and never come down. The speed at which it would have to be thrown to do this is known as escape speed. Of course, we cannot throw a ball hard enough because the speed required to escape completely from the Earth's gravity is seven miles per second, or over twenty-five thousand miles per hour. Once escape speed has been reached by a spacecraft(宇宙飞船), no further power is needed. A rocket aimed at the Moon, for instance, will "coast"(滑行) the rest of the way be cause the Earth's gravity cannot then pull it back, and there is no air resistance(阻力) in space to slow it down. This "coasting" is known as "free fall". That does not mean the rocket is falling down towards the Earth but that it is traveling freely in space without the aid of power, like a bicycle coasting downhill. Free fall is an important feature of space travel: it would be impossible to carry enough fuel to provide powered flight all the time.

单选题"It's been a Uprivilege/U to meet you, sir," the young man said to the artist as he was leaving.

单选题The number of the United States citizens who are {{U}}eligible{{/U}} to vote continues to increase.

单选题The chairman {{U}}proposed{{/U}} that we should stop the meeting.

单选题Against the advice of his accountants, Henry Ford {{U}}regularly{{/U}} reduced the price of his early automobiles.

单选题{{B}}第二篇{{/B}} {{B}} Walking Robot Carries a Person{{/B}} The first walking robot capable of carrying a person unveiled on Friday in Tokyo, Japan. Its creators at Waseda University in Tokyo and the Japanese robotics company Tmsuk hope their two-legged creation will one day enable wheel-chair users to climb up and down the stairs and assist the movement of heavy goods over uneven ground. The battery-powered robot, code-named WL-16, is essentially an aluminium chair mounted on two sets of telescopic poles. The poles are bolted to flat plates which act as feet. WL-16 uses 12 actuators (传动装置) to move forwards, backwards and sideways while carrying an adult weighing up to 60 kilograms (130 pounds). The robot can adjust its body and walk smoothly even if the person it is carrying shifts in the chair. At present it can only step up or down a few millimeters, but the team plans to make it capable of dealing with a normal flight of stairs. "I believe this bipedal (两足的) robot, which I prefer to call a two-legged walking chair rather than a wheel-chair, will eventually enable people to go up and down the stairs," said Atsuo Takanishi, from Waseda University. "We have had strong robots for some time but usually they have been manipulators, they have not been geared to carrying people around," says Ron Arkin, at the Georgia Institute of Technology and robotics consultant for Sony. "But I don't know how safe and how user-friendly WL-16 is." Tmsuk chief executive Yoichi Takamoto argues that bipedal or multi-legged robots will be more useful than so-called "caterpillar (毛毛虫) models" for moving over uneven ground. WL-16's normal walking step measures 30 centimetres, but it can stretch its legs to 136 cm apart. The prototype (原型) is currently radio-controlled, but the research team plans to equip it with a stick-like controller for the user in future. Takanishi said it will take "at least two years" to develop the WL-16 prototype into a working model. Smaller, ground-hugging (紧贴地面行走的) robots have been developed to pass across tricky ground. One maggot-like (像蛆一样的) device uses a magnetic fluid to pulse its way along, while another snake-like robot uses smart software to devise new movement strategies if the landscape affects any one part. One ball-shaped robot even uses a leap-and-bounce approach to travel over rough territory. But none of these are big or strong enough to carry a person too.

单选题The dog saw his Ureflection/U in the pool of water.