单选题The accident was ______ his careless use of gun. A. because of B. owing to C. due to D. on account of

单选题Teachers need to be aware of the emotional, intellectual, and physical changes that young adults experience. And they also need to give serious (1) to how they can be best (2) such changes. Growing bodies need movement and (3) , but not just in ways that emphasize competition. (4) they are adjusting to their new bodies and a whole host of new intellectual and emotional challenges, teenagers are especially self-conscious and need the (5) that comes from achieving success and knowing that their accomplishments are (6) by others. However, the typical teenage lifestyle is already filed with so much competition that it would be (7) to plan activities in which there are more winners than losers, (8) , publishing newsletters with many student-written book reviews, (9) student artwork, and sponsoring book discussion clubs. A variety of small clubs can provide (10) opportunities for leadership, as well as for practice in successful (11) dynamics. Making friends is extremely important to teenagers, and many shy students need the (12) of some kind of organization with a supportive adult (13) visible in the backgound. In these activities, it is important to remember that the young teens have (14) attention spans. A variety of activities should be organized (15) participants can remain active as long as they want and then go on to (16) else without feeling guilty and without letting the other participants (17) .This does not mean that adults must accept irresponsibility. (18) , they can help students acquire a sense of commitment by (19) for roles that are within their (20) and their attention spans and by having clearly stated rules.

单选题 {{I}} Questions 23 and 24 are based on the following news. At the end of the news item, you will be given 10 seconds to answer the questions. Now listen to the news.{{/I}}

单选题Taxation in Roman days apparently was based on ______.

单选题In the Middle East area, oil is found in _________ and its production has been able to keep up with world demand.

单选题The prefix Mach is used to describe supersonic speed. It was named for Ernst Mach (1838-1916), a Czech-born Austrian physicist, who contributed to the study of sound. When twice the speed of sound, it is Mach 2. When it is near but below the speed of sound, its speed can be designated at less than Mach 1. for example, Mach 90. Mach is defined as "the ratio of the velocity of a rocket or a jet to the velocity of sound in the medium being considered." When a plane passes the sound barrier-flying faster than sound travels' listeners in the area hear thunderclaps, but the pilot of the plane does not hear them. Sound is produced by vibrations of an object and is transmitted by alternate increase and decrease in pressure that radiate outward through a material media of molecules--somewhat like waves spreading out on a pond after a rock has been tossed into it. The frequency of sound is determined by the number of times the vibrating waves undulate per second and is measured in cycles per second. The slower the cycle of waves, the lower the frequency. As frequencies increase, the sound is higher in pitch. Sound is audible to human beings only if the frequency falls within a certain range. The human ear is usually not sensitive to frequencies of fewer than 20 vibrations per second, or more than about 20,000 vibrations per second--although this range varies among individuals. Anything at a pitch higher than the human ear can hear is termed ultrasonic. Intensity, or loudness, is the strength of the pressure of these radiating waves and is measured in decibels. The human ear responds to intensity in a range from zero to 120 decibels. Any sound with pressure over 120 decibels is painful to the human ear. The speed of sound is generally placed at 1088 feet per second at sea level at 32 degrees Fahrenheit. It varies in other temperatures and in different media. Sound travels faster in water than in air, and even faster in iron and steel. It travels a mile in 5 seconds in air, it does a mile under water in 1 second, and it travels through iron in 1/3 second. It travels through ice cold vapor at approximately 4,708 feet per second; ice-cold water, 4,938; granite, 12,960; hardwood, 12,620; brick, 11,960, glass. 16,410 to 19,690; silver, 8,658; gold, 5,717.

单选题 Questions 8 to 10 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions. Now listen to the conversation.

单选题He"s ______ as a "bellyacher"—he"s always complaining about something.

单选题______ I would like to stay, I really must go home. A. Much as B. In spite of C. Despite D. As

单选题 George had stolen some money, but the police had caught him and he had been put in prison. Now his trial was about to begin, and he felt sure that he would be found guilty and sent to prison for a long time. Then he discovered that an old friend of his was one of the members of the jury at his trial. Of course, he did not tell anybody, but he managed to see his friend secretly one day. He said to him," Jim, I know that the jury will find me guilty of having stolen the money. I cannot hope to be found not guilty of taking it -- that would be too much to expect. But I should be grateful to you for the rest of my life if you could persuade the other members of the jury to add a strong recommendation for mercy to their statement that they consider me guilty." "Well, George," answered Jim," I shall certainly try to do what I can for you as an old friend, but of course I cannot promise anything. The other eleven people on the jury look terribly strong-minded to me." George said that he would quite understand if Jim was not able to do anything for him and thanked him warmly for agreeing to help. The trial went on, and at last the time came for the jury to decide whether George was guilty or not. It took them five hours, but in the end they found George guilty, with a strong recommendation for mercy. Of course, George was very pleased, but he did not have a chance to see Jim for some time after the trial. At last, however, Jim visited him in prison, and George thanked him warmly and asked him how he had managed, to persuade the other members of the jury to recommend mercy. "Well, George," Jim answered," as I thought, those eleven men were very difficult to persuade, but I managed in the end by tiring them out. Do you know, those fools had all wanted to find you not guilty!"

单选题Which of the following is true about the U.S. Navy underwater listening network?.

单选题In a telephone survey of more than 2,000 adults, 21% said they believed the sun revolved around the earth. An 1 7% did not know which revolved around 2 . I have no doubt that 3 all of these people were 4 in school that the earth revolves around the sun; 5 may even have written it 6 a test. But they never 7 their incorrect mental models of planetary 8 because their everyday observations didn"t support 9 their teachers told them: People see the sun moving 10 the sky as morning tunas to night, and the earth seems stationary 11 that is happening. Students can learn the right answers 12 heart in class, and yet never combined them 13 their working models of the world. The objectively correct answer the professor accepts and the 14 personal understanding of the world can 15 side by side, each unaffected by the other. Outside of class, the student continues to use the 16 model because it has always worked well 17 that circumstance. Unless professors address 18 errors in students" personal models of the world, students are not 19 to replace them with the 20 one.

单选题There has been a great increase in retail sales, ______ . A. does there B. isn't there C. hasn't there D. isn't it

单选题In return for their hospitality, Mr. and Mrs. Brown decided to hold a party to________ their neighbours.

单选题With prices ______ so much, it's hard for the company to plan a budget.

单选题A new technique ______, the yields as a whole increased by 20 percent.

单选题When he tried to make a ______ , he found that the hotel was completely filled because of a convention. A. reservation B. claim C. mess D. revision

单选题{{B}}TEXT E{{/B}} Researchers have established that when people are mentally engaged, biochemical changes occur in the brain that allow it to act more effectively in cognitive areas such as attention and memory. This is true regardless of age. People will be alert and receptive if they are faced with information that gets them to think about things they are interested in. And someone with a history of doing more rather than less will go into old age more cognitively sound than someone who has not had an active mind. Many expert are so convinced of the benefits of challenging the brain that they are putting the theory to work in their own lives." The idea is no necessarily to learn to memorize enormous amounts of information," says James Fozard, associate director of the National Institute on Aging." Most of us don' t need that kind of skill. Such specific training is of less interest than being able to maintain mental alertness." Fozard and others say they challenge their brains with different mental skills, both because they enjoy them and because they are sure that their range of activities will help the way their brains work. Gene Cohen, acting director of the same institute, suggests that people in their old age should engage in mental and physical activities individually as well as in groups. Cohen says that we are frequently advised to keep physically active as we age, but older people need to keep mentally active as well. Those who do are more likely to maintain their intellectual abilities and to be generally happier and better adjusted." The point is, you need to do both," Cohen says," Intellectual activity actually influences brain-cell health and size."