Today, ultrasonic(超声的) waves are being put to work in laboratories and factories. If an ultrasound generator is placed in a liquid, the waves move the liquid back and forth hundreds of thousands of times each second. This causes materials to mix quickly or to dissolve(使分解，使溶解) in liquids. Paint manufacturers(制造商) use ultrasound to do a better job of blending colors. The companies that make film for your camera find that mixing chemicals by the use of sound waves will produce a more sensitive film.
The new lightweight(轻量的) type of washing machine uses ultrasonic waves to get clothes clean. Its special ultrasound generator is put into a pail of soapy water containing the soiled clothes. The sound waves drive the soapy water back and forth through the cloth so fast that everything is soon clean. There is also a new kind of dishwasher that works in much the same way.
Ultrasonic waves can shake a liquid so fast that tiny holes form all through it. The liquid is actually torn apart by this action. Almost as soon as these holes are made, they fall together again. The result is a powerful pounding action. In the dairy industry this is used for the double purpose of making homogenized(使均匀，使匀质) milk and sterilizing(使无菌) it at the same time. If you look at some raw milk with a microscope, you find that it is made up of little drops of butter fat floating around in a watery liquid. In order to make milk easier to digest, these fat droplets(微粒) may be broken up by forcing the milk through very small openings. The result is called homogenized milk. When the ultrasonic method is used, the sound waves not only break up the droplets but also kill the germs in the milk by pounding them to pieces. (from www.nmet84.com)
8. Why does a paint manufacturer use ultrasound to do a better job of blending colors?
A. Because it is cheap to use ultrasound to blend colors.
B. Because the waves move the liquid so quickly that it can make materials mix quickly or dissolve in liquids.
C. Because they can mix chemicals by the use of sound waves.
D. Because the waves can clean the paint.
9. What properties does ultrasound wave have?
A. Homogenizes and sterilizes the milk. B. Mix materials and break droplets.
C. Kill germs and sterilize milk. D. Move liquids quickly.
10. What exists in the raw milk?
A. Little drops of butter fat. B. Small holes. C. Fat droplets and germs. D. Chemicals.
11. Where is ultrasound wave not used?
A. In the paint manufacture. B. In the shop mixing bread flour.
C. In the film-making company. D. In the dairy industry.
In Britain today, is it possible to tell a person’s class just by looking at him? Physical details alone tell us about health, diet and the type of work a person does. A hundred years ago the working class often looked unhealthy, small and they were either too thin or too fat. The upper classes were often tall, sporting types who were used to a good diet and looked healthy. Today living and working conditions have improved, and such descriptions are no longer true. People are taller now than a hundred years ago. Everyone in Britain today is able to have free medicine, a good diet, acceptable working conditions and enough rest and leisure. WWW.K**S*858$$U.COM
The clothes people choose to wear, however, do provide information about their backgrounds. Expensive clothes look expensive and show their wearer is rich. Clothes can provide other clues as well. The upper classes appear to be less interested in fashion and wear good quality clothes in non-bright colours, made of natural material like wool, leather and cotton. Lower working-class people often choose clothes in bright colours, made of man-made materials. A sociological explanation for this would be that colour and interest are missing from their lives, and therefore any opportunity to produce this is taken.
Clothes are available at a price within most people’s reach. New clothes make the wearer feel good and show some degree of wealth to the outside world. Today it is the younger people who spend most money on clothes. Fashion is no longer for the upper classes and the rich. Young people from all social classes spend a lot of money on clothes. Some new fashions are started by working-class people who want to look different and feel important. They want people WWW.K**S*858$$U.COMto look at them.In the past, a person’s appearance could not tell other people about his ________.
| A．health | B．diet | C．occupation (职业) | D．habits |
The clothes people choose to wear tell us about their ________.
| A．education | B．richness | C．backgrounds | D．hobby |
A working-class person may start a new fashion because ________.
| A．she wants to draw the attention of other people |
| B．she wants to look different and healthy |
| C．she wants to show their wealth |
| D．she wants to show their taste |
Which of the following statements is NOT true?
| A．Expensive clothes look expensive and show the wearer is rich. |
| B．Working-class people prefer clothes in bright colours because they lack colour in their lives. |
| C．Today, it is still the upper class people who spend most money on clothes. |
| D．Today, fashion is no longer for the upper classes and the rich. |
There is an endless supply of stories about sleepwalkers (梦游者). People have been said to climb on roofs, solve mathematical problems, write music, walk through windows, and do murder in their sleep.
In Revere, Massachusetts, a hundred policemen searched for a lost boy who left his home in his sleep and woke up five hours later on a strange sofa in a strange living room, with no idea how he had got there.
At the University of Lowa, WWW.K**S*858$$U.COMa student was reported to have the habit of getting up in the middle of the night and walking three-quarters of a mile to the Lowa River. He would take a swim and then go back to his room to bed.
An American expert on sleep claims (声称) that he has never seen a sleepwalker. He is said to know more about sleep than any other living man, and during the last thirty-five years he has lost a lot of sleep watching people sleep. He says, “Of course, I know that there are sleepwalkers because I have read about them in the newspapers. But none of my sleepers ever walked, and if I were to advertise for sleepwalkers for an experiment, I doubt whether I would get many takers (应征者).”
Sleepwalking, however, is a scientific reality. It is one of those strange things that sometimes look quite fantastic (怪诞的). Doctors say that sleepwalking is much more common than is generally supposed. Many sleepwalkers do not try to find help and their sleepwalking is never recorded. Generally speaking, sleepwalkers are people who ________.
| A．climb on roofs | B．walk through windows |
| C．do fantastic things during their sleep | D．walk in a half-awake state |
It was reported that a boy ________.
| A．was found on a strange sofa, telling how he had got there |
| B．slept in his own room but woke up in a strange room |
| C．lost his way five hours after he left home |
| D．was searched for by policemen when he lost his way |
There was a college student who got into the habit of ________.
| A．getting up in the middle of the night and walking down to the river |
| B．walking three-quarters of a mile every day |
| C．swimming in the Lowa River before going to bed |
| D．walking about before he went to bed |
Why do people think sleepwalking is nothing but a fantastic thing which doesn’t have any explanation?
| A．It is so common that it needn’t be recorded. |
| B．Scientists take no interest in it. |
| C．Most sleepwalkers do not seek help for their problem. |
| D．No records about it have been made. |
In 1999, twelve percent of public elementary schools in the United States required students to wear uniforms. Just three years later, the amount was almost double that.
A study of six big-city Ohio public schools showed students who were required to wear uniforms had improved graduation, behavior and attendance rates. Academic performance was unchanged.
Some high schools in Texas have also joined in the movement. Yet studies find mixed results from requiring uniforms. And some schools have turned away from such policies.
Supporters believe dressing the same creates a better learning environment and safer schools. The school district in Long Beach, California, was the first in the country to require uniforms in all elementary and middle schools. The example helped build national interest in uniforms as a way to deal with school violence and improve learning.
Findings in Long Beach suggested that the policy resulted in fewer behavior problems and better attendance. But researcher Viktoria, who has looked at those findings, says they were based only on opinions about the effects of uniforms.
She says other steps taken at the same time to improve schools in Long Beach and statewide could have influenced the findings. The district (the area marked by government) increased punishments for misbehavior. And California passed a law to reduce class sizes.
In Florida, for example, researcher Sharon found that uniforms seemed to improve behavior and reduce violence. In Texas, Eloise found fewer discipline problems among students required to wear uniforms, but no effect on attendance.
Sociologist David has studied school uniform policies since1998．He collected the reports in the book. In his own study, he found that reading and mathematics performance dropped after a school in Pennsylvania(宾夕法尼亚州) required uniforms.
Political and community pressures may persuade schools to go to uniforms to improve learning. But David and others believe there is not enough evidence of a direct relationship. In fact, he says requiring uniforms may even increase discipline problems. Which of the following researchers are NOT supporters of school uniform policies?
| A．Viktoria and Sharon. | B．Sharon and David. |
| C．Eloise and Sharon. | D．Viktoria and David. |
The underlined word“misbehavior”in the sixth paragraph probably means ________.
| A．serious crime | B．bad performance |
| C．absence for class | D．action against wearing uniforms |
What can we infer from the passage?
| A．More work is needed to get better information about uniform’s effect. |
| B．The number of schools requiring uniforms in the U.S. will become less sharply. |
| C．Wearing uniforms has little to do with behavior and learning. |
| D．Politicians and communities won’t vote for uniform policies. |
What’s the main idea of this passage?
| A．More and more students are required to wear uniforms in the U.S. |
| B．Wearing uniforms contributes to good academic performance. |
| C．Researchers in the U.S. argue for school uniform policies. |
| D．Evidence for school uniform polices in the U.S. is seen as weak. |
When other nine-year-old kids were playing games, she was working at a petrol station. When other teens were studying or going out, she struggled to find a place to sleep on the street. But she overcame these terrible setbacks to win a highly competitive scholarship and gain entry to Harvard University. And her amazing story has inspired a movie,“Homeless to Harvard: The Liz Murray Story”, shown in late April.
Liz Murray, a 22-year-old American girl, has been writing a real-life story of willpower and determination. Liz grew up in the shadow of two drug-addicted parents. There was never enough food or warm clothes in the house. Liz was the only member of the family who had a job. Her mother had AIDS and died when Liz was just 15 years old. The effect of that became a turning point in her life. Connecting the environment in which she had grown up with how her mother had died, she decided to do something about it.
Liz went back to school. She threw herself into her studies, never telling her teachers that she was homeless. At night, she lived on the streets.“What drove me to live on had something to do with understanding, by understanding that there was a whole other way of being. I had only experienced a small part of the society,”she wrote in her book Breaking Night.
She admitted that she used envy to drive herself on. She used the benefits that come easily to others, such as a safe living environment, to encourage herself that“next to nothing could hold me down”. She finished high school in just two years and won a full scholarship to study at Harvard University. But Liz decided to leave her top university a couple of months earlier this year in order to take care of her father, who has also developed AIDS.“I love my parents so much. They are drug addicts. But I never forget that they love me all the time.”
Liz wants moviegoers (who often see films) to come away with the idea that changing your life is“as simple as making a decision”.In which order did the following things happen to Liz?
A．Her mother died of AIDS. B．She worked at a petrol station.
C．She got admitted into Harvard. D．The movie about her life was put on.
e. She had trouble finding a place to sleep.
A．b, a, e, c, d B．a, b, c, e, d C．e, d, b, a, c D．b, e, a, d, cThe main idea of the passage is ________.
| A．how Liz managed to enter Harvard University |
| B．what a hard time Liz had in her childhood |
| C．why Liz loved her parents so much |
| D．how Liz struggled to change her life |
What actually made her go towards her goal?
| A．Envy and competition. | B．Willpower and determination. |
| C．Decisions and understanding. | D．Love and respect for her parents. |
When she wrote“What drove me to live on...I had only experienced a small part of the society”, she meant that ________.
| A．she had little experience of social life |
| B．she could hardly understand the society |
| C．she would do something for her own life |
| D．she needed to travel more around the world |
Until late in the 20th century most Americans spent time with people of different generations. Now middle-aged Americans may not keep in touch with old people until they are old themselves.
That's because we group people by age. We put our three-year-olds together in day-care centers, our 13-year-olds in schools and sport activities, and our 80-year-olds in senior citizen homes. Why?
We live far away from the old for many reasons. Young people sometimes avoid the old to get rid of fears of becoming old and dying. It is much harder to watch someone we love disappear before our eyes. Sometimes it’s got hard that we stay away from the people who need us the most.
Fortunately, some of us have found our way to the old. And we have discovered that they often save the young.
A reporter moved her family into a block filled with old people. At first her children were disappointed. But the reporter made banana bread for the neighbors and had her children send it and visit them. Soon the children had many new friends, with whom they shared food, stories and projects. "My children have never been lonely, "the reporter said.
The young, in turn, save the old. Once I was in a rest home (an organization where old people are cared for) when a visitor showed up with a baby, she was immediately surrounded. People who hadn't gotten out of bed in a week suddenly were ringing for a wheelchair. Even those who had seemed asleep woke up to watch the child. Babies have an astonishing power to comfort and cure.
Grandparents are a special case. They give their grandchildren a feeling of security and continuity. As my husband put it "My grandparents gave me a deep sense that things would turn out right in the end." Grandchildren speak of attention they don't get from worried parents. "My parents were always telling me to hurry up, and my grandparents told me to slow down," one friend said. A teacher told me she can tell which pupils have relationships with grandparents: they are quieter, calmer and more trusting.Now in an American family, people can find that___________.
| A．children never live with their parents |
| B．not all working people live with their parents |
| C．old people are supported by their grandchildren |
| D．grandchildren are supported by their grandparents |
Seeing a baby, the old people got excited because _______.
| A．they had never seen a baby before |
| B．the baby was clever and beautiful |
| C．the baby brought them the image of life |
| D．the baby's mother would take care of them |
Why are some children quieter, calmer and more trusting ?
| A．Because they have relationships with their grandparents. |
| B．Because their worried parents ask them to act like that. |
| C．Because they have nothing to worry about. |
| D．Because their teachers ask them to act like that. |
Which of the following can show the fact that the old often save the young?
| A．The old can become friends of the children and the children may not feel lonely. |
| B．The old get excited when they see a baby. |
| C．The old can cure the young when they are sick. |
| D．Babies have an astonishing power to comfort and cure. |