单选题 Memory is the ability to keep track of things that have happened in the past. Memory really is learning. One needs memory to ride a bicycle. A dog needs to remember if it is to come when called. Memory is said to be stored in the brain as a 'memory trace (记忆痕) '. What makes up this trace is not known. Some scientists believe that certain chemical substances may carry certain memories. For example, one substance, when given to rats, causes them to fear the dark. Other research into memory has to do with how the brain works. Psychologists use three means to find out bow a person remembers. For example, give a person a grocery list. Let the person memorize the list, then put it away. The most natural way to find out how much a person remembers of the grocery list is to ask what he or she remembers. This is called the method of recall. Another method is called recognition. Give the person another grocery list. Ask him or her to choose items on the first list from the items that are on only the second list. Often a person will be able to recognize things that he or she cannot recall. A third method of finding how much a person remembers is called relearning. Here the person is asked to read over the first list. The person will probably learn the list the second time faster than he did the first time. The difference in the time it takes to relearn the list is thought of as measure of how much a person has remembered. One way of remembering something is to repeat it many times. Interest is very important. Boring lists of facts are much more difficult to remember than something that we understand and are interested in. Motivation, or wanting to do something, is also important. Motivation is linked with reward. For example, a hungry animal quickly learns how to do something if that action gets the animal food. In humans, wanting to learn is often motivation. The praise of a teacher or the knowledge that an answer is correct is rewarding.

单选题 A number is an abstraction ______ no physical existence.

单选题Dave:What sports do you like?Rita:I like basketball.Dave:Why do you like it?Rita:_____56_____Dave:Do you want to play it now?Rita:_____57_____Dave:What movie?Rita:_____58_____Dave:But I don′t think so

单选题 For the sake of your health, you should give up smoking ______.

单选题 Every day, about one-quarter of American adults eat at fast-food restaurants. Cheap, tasty, and convenient, fast food is rich in fat and calories, and it's low in fiber and nutrients. Thanks in large part to fast food, half of America's adults and one-quarter of its children are fat, double the rate of a generation ago. In the past two decades, eating habits have changed as people pay more attention to their health. However, many Americans continue to eat red meat (beef in particular) as well as pork, chicken and other foods. Although beer and wine are popular in most areas, many Americans abstain from alcohol, because they think they will become healthier without drinking it. Various kinds of mineral water are commonly available. Eating styles and habits vary between people of different backgrounds, but Americans generally eat with the fork in the hand with which they write. A knife is used for cutting and spreading; otherwise, it is laid on the plate or table. Fast foods, such as chips, fried chicken, hamburgers, and pizza, tend to be eaten with the fingers. There is an obvious difference between what people may do at home or in a fast-food restaurant, and how they act in a more formal restaurant. Because both parents often work outside the home, some Americans are less likely to sit down as a family to eat once the children are older and able to prepare their own food or serve themselves.

单选题 Mr. Smith ______ working till he was seventy years old.

单选题 Mike's uncle insists ______ in this hotel.

单选题 When I was a child I used ______ swimming in the lake.

单选题 Water is ______ hydrogen and oxygen.

单选题 The flying fox is not a fox at all. It is an extra large bat that has got a fox's head, and that feeds on fruit instead of insects. Like all bats, flying foxes hang themselves by their toes when it rest, and travel in great crowds when out flying. A group will live in one spot for years. Sometimes several hundreds of them occupy (占据) a single tree. As they return to the tree toward sunrise, they quarrel among themselves and fight for the best places until long after daylight. Flying foxes have babies once a year, giving birth to only one at a time. At first the mother has to carry the baby on her breast wherever she goes. Later she leaves it hanging up, and brings back food for it to eat. Sometimes a baby falls down to the ground and squeaks (尖叫) for help. Then the older ones swoop (俯冲) down and try to pick it up. If they fail to do so, it will die. Often ten hundreds of dead baby bats can be found lying on the ground at the foot of a tree.

单选题 Keeping pace with teachers is a fine way to study English. Teachers are experienced and their plans are systematic. But remember to work in a way that suits you. It's important to learn from past mistakes as well. Keep a notebook to make a record of the mistakes you make—it'll help you avoid making the same ones later. The time of life may be hard, but you're not alone. You may be busy studying, but you can show your care by calling your friends or sending short messages. Don't let your friendships die. It's as important to live well as it is to study well. Going to bed no later than 11:30 pm is vital. It puts you in the right mood for the next day. You needn't follow a special diet, but make sure you are eating nutritious meals each day. The person who plays well, studies well. Having a lot of schoolwork doesn't mean having to give up other activities. Playing basketball or having a talk with your classmates can relax yourself. Time-out is not a waste of time but helps you study more efficiently. Besides taking the big exam, you have other choices for college. I took the independent enrollment exam held by Peking University and some other students even were preparing to study abroad. Pay attention to any relevant information you can find, whether it's from school, the news media or other sources.

单选题 Mr. And Mrs. Smith had always spent their summer holidays in New Jersey in the past, staying in a small inn at the foot of a hill. One year, however, Mr. Smith made a lot of money in his business, so they decided to go to London and stay at a really good hotel while they went touring around that famous city. They flew to London and arrived at their hotel late one evening. They expected that they would have to go to bed hungry, because in that small inn in New Jersey no meals were served after seven. They were therefore surprised when the man who received them in the hall asked whether they would ask dinner there that night. 'Are you still serving dinner?' asked Mr. Smith. 'Yes, certainly, sir,' answered the man. 'We serve it until half past nine.' 'What are the times of meals then?' asked Mr. Smith. 'Well, Sir,' answered the man, 'We serve breakfast from seven to half past eleven in the morning, lunch from twelve to three in the afternoon, tea from four to five and dinner, from six to half past nine.' 'But that hardly leaves any time for us to see the sights of London.' Said Mrs. Smith.

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单选题 ______ experiments on the laboratory, it started to rain heavily.

单选题__________parents say and do has a life-long effect on their children.

单选题 —Have you seen Jack and John? —I haven't seen ______ of them.

单选题 ______ , always boasting about something great he has done.

单选题 We show an amazing tolerance for a form of pollution that is a growing problem: noise. Airplane traffic is increasing by five percent a year. Urban noise is doubling every ten years. By air, land and sea, we are facing an onslaught of noise that is threatening our ability to live in this world. We have granted ourselves the right to make noise. But what about our responsibilities? Have we developed a sense of acoustic responsibility? The evidence suggests that we have not. Many people seem to believe they have an unlimited right to make noise with cars and motorbikes, and with loud music at home and in the street. In some countries measures have been taken to force people to make less noise. In Britain, for example, a law has been passed preventing people from disturbing their neighbors with music at night. It is widely accepted that we should deal with our rubbish in a responsible way. Noise is in reality a particularly insidious (潜在的) form of rubbish. It destroys community life, pursues us into our homes, keeps us from sleeping and is the cause of many stress-related illnesses, as well as hearing loss. Our acoustic environment belongs to all of us. Everyone has the right to use it, but no one has the right to abuse it. Let's start using it responsibly.

单选题 They were ______ for a honeymoon after their wedding ceremony.

单选题 When people ask him for help, he never turned his back ______ them.