Broken rubber bands and flat tires requiring replacement could soon be a thing of the past.
French researchers have developed a new kind of rubber that can repair itself when broken.The new rubber is made from widely available materials including vegetable oil and a common industrial chemical.All the materials are considered safe to the environment and can be easily reused.
The best part is that the new rubber can be repaired and used again and again without losing its strength or ability or stretch.When cut, the rubber can be made new again, simply by pressing the two broken ends back together.
The product can be repaired at room temperature, around twenty degrees Centigrade;other self-healing materials require higher temperatures for repair.
Traditionally, rubber substances are made from huge molecules(分子)connected by strong chemical links, or bonds.The new rubber is made of smaller molecules.The molecules are linked together using hydrogen bonds.When connected in this way, the molecules act like one long molecule, forming what is called supramolecular networks(超分子网).When the rubber is cut, the molecules attempt to connect with whatever molecule is near them.When pressed together, the molecules are able to repair themselves at the molecular level, making the repaired rubber like new.
However, time is an important element in the process.If the broken ends are not brought together quickly, a repair is not possible.This is because molecules will form bonds with molecules on their own side.The inventors say the surfaces of the rubber can be repaired within a week of being separated.
The rubber is the creation of scientists at the Industrial Physics and Chemistry Higher Education Institution in Paris.The organization is part of France's National Center for Scientific Research.The new material is described in greater detail in the research publication Nature.
According to the introduction, which of the following is NOT the advantage of the new rubber?
A.It can be made as easily as common rubber. |
B.It is environmentally-friendly. |
C.It can repair itself at room temperature. |
D.It is made of smaller molecules. |
What does the 5th paragraph mainly tell us?
A.Why t![]() |
B.Why the new rubber can repair itself. |
C.The new rubber is made from huge molecules. |
D.The new rubber is different from the common rubber. |
If we want to know more about the technology of this kind of new rubber, where can we get the information?
A.In the researchers' diary. | B.In a guide book. |
C.In a research magazine. | D.In a newspaper. |
Large companies need a way to reach the savings of the public at large. The same problem, on a small scale, faces practically every company trying to develop new products and create new jobs. There can be little prospect of raising the sort of sums needed from friends and people we know, and while banks may agree to provide short-term finance, they are generally unwilling to provide money on the permanent basis for long-term projects. So companies turn to the public, inviting people to lend them money, or take a share in the business through the Stock Exchange. By doing so, they can put the saving of individuals and institutions into circulation both at home and overseas.
When the saver needs his money back, he does not have to go to the company with whom he originally placed it. Instead, he sells his shares through a stockbroker(股票经纪人) to some other saver who is seeking to invest his money.
Many of the services needed both by industry and by each of us are provided by the government or by local authorities. Without hospitals, roads, electricity, telephones, railways, this country could not function. All these require continuous spending on new equipment and new development if they are to serve us properly, requiring more money than is raised through taxes alone. The government, local authorities, and nationalized industries therefore frequently need to borrow money to finance major capital spending, and they, too, come to the Stock Exchange.
There is hardly a man or woman in this country whose standard of living does not depend on the ability of his or her employers to raise money to finance new development. In one way or another, the new money must come from the savings of the country. The Stock Exchange exists to provide a channel through which these savings can reach those who need finance.
51. Almost all companies involved in new production and development most .
A. rely on their own resources
B. persuade the banks to provide long-term finance
C. borrow large sums of money from friends and people they know
D. depend on the population as a whole for finance
52. The money which enables these companies to go ahead with their projects is .
A. repaid to its original owners as soon as possible
B. raised by selling of shares in the companies
C. exchanged for the ownership in the Stock Exchange
D. invested in different companies in the Stock Exchange
53. When the savers want their money back they should .
A. ask another company to obtain their money for them
B. look for other people to borrow money from
C. put their shares in the company back on the market
D. transfer their money to a more successful company
54. All the essential services on which we depend are .
A. run by the government or our local authorities
B. in constant need of financial support
C. financed wholly by raising taxes
D. unable to provide for the needs of the population
55. The Stock Exchange makes it possible for the government, local authorities and nationalized industries .
A. to borrow as much money as they wish
B. to make certain everybody saves money
C. to raise money to finance new development
D. to make certain everybody lends money to them.
In the United States, friendships can be close, constant, intense, generous, and real, yet fade away in a short time if circumstances change. Neither side feels hurt by this. Both may exchange Christmas greetings for a year or two, perhaps a few letters for a while — then no more. If the same two people meet again by chance even years later, they pick up the friendship where it left off and are delighted.
In the States, you can feel free to visit people’s homes, share their holidays, enjoy their children and their lives without fearing that you are taking on a lasting obligation. Do not hesitate to accept hospitality because you cannot give it in return. No one will expect you to do so for they know you are far from home. Americans will enjoy welcoming you and be pleased if you accept their hospitality easily.
Once you arrive there, the welcome will be full and warm and real. Most visitors find themselves readily invited into many homes there. In some countries it is considered inhospitable to entertain at home, offering what is felt as “merely” home cooked food, not " doing something" for your guest. It is felt that restaurant entertaining shows more respect and welcome. Or for various other reasons, such as crowded space, language difficulties, or family customs, outsiders are not invited into homes.
In the United States, both methods are used, but it is often considered more friendly to invite a person to one’s home than to go to a public place, except in purely business relationships. So, if your host or hostess brings you home, do not feel that you are being shown inferior(次等的) treatment.
Don’t feel neglected if you do not find flowers awaiting you in your hotel room either. Flowers are very expensive there, and hotel delivery is uncertain that the arrival times are delayed, changed, or canceled—so flowers are not customarily sent as a welcoming touch. Please do not feel unwanted. Outward signs vary in different lands; the inward welcome is what matters, and this will be real.
46. In the United States, you will find friendships if circumstances change.
A. die suddenly B. pass away
C. disappear gradually D. last forever
47. Americans their foreign friends to make a return for their-hospitality.
A. ask B. wish
C. never allow D. don't expect
48. In some other countries, giving a dinner party at home is considered than in a restaurant.
A. less friendlyB. less hospitable
C. more natural D. more popular
49. According to the passage, which of the following is NOT true?
A. Flowers are available at all times.
B.Flowers are expensive.
C.Flowers are signs of outward welcome.
D.Flowers are not necessarily sent to guests.
50. Which of the following is the best title for this passage?
A. American Hospitality. B. American Friendship.
C. American Invitation. D. American Welcome.
Ⅳ. 阅读理解(共20题;每小题2分,满分40分)
第一节阅读理解(共15小题;每小题2分,满分30分)
阅读下列短文,从每题所给A, B, C和 D项中,选出最佳选项。
In an age when technology moves faster than most can keep up with, a small group of people still remain in the time of old-fashioned letters. Frankly speaking, I was once certain that traditional letters could never be replaced by other means of communication.
But a story about online communication changed my mind.
An old man, who suffered a lot from Parkinson's disease, was not able to talk clearly and could hardly write his name. Living totally alone, he managed to keep in touch with nearly all the members of his family. How did he achieve this? He clicked out words on his computer keyboard.
I, therefore, managed to get an e-mail box as soon as the opportunity came. My life changed. E-mail, and all online communication, is something truly different. It has capabilities that few other products can match.
E-mail is convenient. It takes less time with its fast speed and 24-hour connection. The slow postal service is no match. If you wouldn't want to have a face-to-face talk with your manager, you might talk with him through e-mail even if you are in the same office.
Naming all the good things about online communication is not easy. But wait. E-mail can be inconvenient. It can waste time and energy. Just think what may happen when you take a short vacation and return to find your e-mail box filled with 200 unread messages. You could clearly spend half a day clearing junk ads.
Then, online communication will keep us staying at our computer while it connects us to distant strangers. Once we throw ourselves into the machine, we may forget the human touches we once held so dear. I'm sure there's and always will be a place for the old-fashioned letter, phone call, and face-to-face meeting even in the world of modem communication.
As I listen to the sound of the modem, I was excited at stepping out to the outside world but, at the same time, I sensed a loss of control over something valuable in my personal life.
41. What caused the writer to become interested in e-mail and online communication?
A. The sound of the modem. B. His own illness.
C. The changing of his life. D. A sick old man's experience.
42. What is the most probable meaning of the underlined word "junk" in Paragraph 7?
A. Old and useless. B. New and useful.
C. Short but valuable. D. Long but clear.
43. What does the writer think of online communication?
A. It should replace old-fashioned letters completely.
B. It is perfectly and always does good to you.
C. It is extremely useful and convenient, but it may be inconvenient or even harmful.
D. It does more harm than good.
44. How did the sick old man keep in touch with his family members?
A. With the help of his computer.
B. By writing letters with his pen.
C. By making telephones calls.
D. By visiting them regularly.
45. According to the writer, traditional means of communication will never disappear because.
A. they are convenient and popular though they are slow
B. they help to keep the friendly relationship between people
C. most people cannot keep up with the development of technology
D. modem means of communication does too much harm
A friend of mine named Paul received an expensive car from his brother as a Christmas present.On Christmas Eve when Paul came out of his office, a street urchin (顽童) was walking around the shining car.“Is this your car, Paul?” he asked.
Paul answered, “Yes, my brother gave it to me for Christmas.” The boy was surprised.“You mean your brother gave it to you and it cost you nothing? Boy, I wish…” He hesitated.
Of course Paul knew what he was going to wish for.He wished he had a brother like that.But what the boy said surprised Paul greatly.
“I wish,” the boy went on, “that I could be a brother like that.” Paul looked at the boy in surprise, and then he said again, “Would you like to take a ride in my car?”
“Oh yes, I’d love that.”
After a short ride, the boy turned and with his eyes shining, said, “Paul, would you mind driving in front of my house?”
Paul smiled a little.He thought he knew what the boy wanted.He wanted to show his neighbors that he could ride home in a big car.But Paul was wrong again.“Will you stop where those two steps are?” the boy asked.
He ran up to the steps.Then in a short while Paul heard him coming back, but he was not coming fast.He was carrying his little crippled (残疾) brother.He sat him down on the step and pointed to the car.
“There she is, Buddy, just like I told you upstairs.His brother gave it to him for Christmas and it didn’t cost him a cent.And some day I’m going to give you one just like it… Then you can see for yourself all the nice things in the Christmas window that I’ve been trying to tell you about.”
Paul got out and lifted the boy to the front seat of his car.The shining-eyed older brother climbed in and the three of them began an unforgettable holiday ride.
1.The street urchin was very surprised when __________.
A.he saw the shining car
B.Paul told him about the car
C.he was walking around the car
D.Paul received an expensive car
2.From the story we know that the urchin __________.
A.wished to give his brother a car
B.wished Paul’s brother to give him a car
C.wished Paul could be a brother like that
D.wished he could have a brother like Paul’s
3.The urchin asked Paul to stop his car in front of his house ______.
A.to show he had a rich friend
B.to show his neighbors the car
C.to let his brother ride in the car
D.to tell his brother about his wish
4.We can infer from the story that __________.
A.Paul couldn’t understand the urchin
B.the urchin’s wish came true in the end
C.the urchin wished to have a rich brother
D.the urchin had a deep love for his brother
5.The best title for the story probably is __________.
A.A Christmas Present B.A Street Urchin
C.A Brother Like That D.An Unforgettable Ride
Doctors have known for a long time that extremely loud noises can cause hearing damage or loss.The noise can be the sound of a jet airplane or machines in factories of loud music or other common sound at home and at work.A person only needs to hear the noise for little more than one second to be affected.
An American scientist has found that using aspirin (阿斯匹林) increase the temporary (暂时的)hearing loss or damage from loud noise.He did an experiment using a number of students at a university who all had normal hearing.He gave them different amounts of aspirin for different periods of time, then he tested their hearing ability.He found that students who were given four grams of aspirin a day for two days suffered much greater temporary hearing loss than those who did not use aspirin.The hearing loss was about two times as great.
The scientist said millions of persons in the U.S.use much larger amounts of aspirin than were used in his experiment.He said these persons face a serious danger of suffering hearing loss from loud noise.
1.Doctors have long known that__________.
A.one may lose his hearing when he hears a terribly loud noise.
B.one may become deaf when he hears a loud noise.
C.loud noises can cause damage to the hearing of the young people only
D.common sounds at home are not harmful to the ear
2.This passage suggests that one’s hearing________.
A.will be damaged even if he has heard a loud noise for only little more than one second
B.will be damaged even if he has heard a loud noise less than one second
C.will not be damaged if he has heard a loud noise for only little more than one second
D.will not be damaged if he has little more than one second to get ready
3.One conclusion you can draw from the passage is that aspirin________.
A.makes hearing damage from loud noise worse
B.should never be taken more than four grams
C.can damage one’s hearing when it is given more than four grams daily
D.always increases hearing loss by two times
4.Millions of Americans are in danger of suffering hearing loss because they__________.
A.take too much aspirin
B.often take air trips
C.like listening to loud music
D.have too much loud noises at home and at work
5.The American scientist did his experiment in order to find ________.
A.how much aspirin would affect a person’s hearing
B.how much aspirin should be given in the treatment of the patients with hearing damage from loud noise
C.whether aspirin would increase the temporary hearing damage from loud noises
D.whether the people who had hearing damage should use aspirin