Knots are the kind of stuff that even myths are made of.In the Greek legend of the Gordian knot, for example, Alexander the Great used his sword to slice through a knot that had failed all previous attempts to unite it. Knots, enjoy a long history of tales and fanciful names such as “Englishman’s tie, ” “and “cat’s paw. ” Knots became the subject of serious scientific investigation when in the 1860s the English physicist William Thomson (known today as Lord Kelvin) proposed that atoms were in fact knotted tubes of ether（醚）. In order to be able to develop the equivalent of a periodic table of the elements, Thomson had to be able to classify knots — find out which different knots were possible. This sparked a great interest in the mathematical theory of knots.
A mathematical knot looks very much like a familiar knot in a string, only with the string’s ends joined. In Thomson’s theory, knots could, in principle at least, model atoms of increasing complexity, such as the hydrogen, carbon, and oxygen atoms, respectively. For knots to be truly useful in a mathematical theory, however, mathematicians searched for some precise way of proving that what appeared to be different knots were really different — the couldn’t be transformed one into the other by some simple manipulation（操作）. Towards the end of the nineteenth century, the Scottish mathematician Peter Guthrie Tait and the University of Nebraska professor Charles Newton Little published complete tables of knots with up to ten crossings. Unfortunately, by the time that this heroic effort was completed, Kelvin’s theory had already been totally discarded as a model for atomic structure. Nevertheless, even without any other application in sight, the mathematical interest in knot theory continued at that point for its own sake. In fact, mathematical became even more fascinated by knots. The only difference was that, as the British mathematician Sir Michael Atiyah has put it, “the study of knots became a special branch of pure mathematics. ”
Two major breakthroughs in knot theory occurred in 1928 and in 1984. In 1928, the American mathematician James Waddell Alexander discovered an algebraic expression that uses the arrangement of crossings to label the knot. For example, t2-t+1 or t2-3t+1, or else. Decades of work in the theory of knots finally produced the second breakthrough in 1984. The New Zealander-American mathematician Vaughan Jones noticed an unexpected relation between knots and another abstract branch of mathematics, which led to the discovery of a more sensitive invariant known as the Jones polynomial.What is surprising about knots?
| A．They originated from ancient Greek legend. |
| B．The study of knots is a branch of mathematics. |
| C．Knots led to the discovery of atom structure. |
| D．Alexander the Great made knots well known. |
What does the underlined word “that” in Paragraph 3 refer to?
| A．No other application found except tables of knots. |
| B．The study of knots meeting a seemingly dead end. |
| C．Few scientist showing interest in knots. |
| D．The publication of complete tables of knots. |
According to the passage, ______ shows the most updated study about knots.
| A．t2-t+1 | B．t2-3t+1 |
| C．Alexander polynomial | D．Jones polynomial |
Which one would be the best title for this passage?
| A．Mathematicians VS Physicians |
| B．To be or Knot to be |
| C．Knot or Atom |
| D．Knot VS Mathematics |
After the Summer Olympics are over, when all the athletics have gone home and the television audience has switched off, another group of athletics and fans will arrive at the host city, and another competition will begin. These are the Paralympics, the games for athletes with a disability. But in Beijing in 2008, for the first time, one of the greatest Paralympics will not be taking part.
She is a British athlete by the name of Tanni Grey-Thormpson. Born with spine hifida (脊椎裂) which left her paralysed from the waist down. Tanni used a wheelchair from the age of 7. at first, she was not keen on sport, apart from horse-riding, which gave her a sense of freedom. But in her teens, she started taking sports more seriously. She tried swimming, basketball and tennis. Eventually she found athletics, and never looked back.
Indeed, Tanni's athletic career took off. In 1984, when she was 15, she pulled off a surprise victory in the 100metres at the Junior National Wheelchair Games.
In 1988, Tanni went to her first Paralympic Games in Seoul. She won bronze in the 400 metres. Even greater success followed at the 1992 Barcelona. Paralympics. Tanni won gold in the 100, 200, 400 and 800 metres relay, setting two world records in the process. In the same year she achieved she first of her six London Wheelchair Marathon victories.
Tanni's enduring success had been part motivation(动机), part preparation, "The training I do that enables me to be a good sprinter(短跑运动员) enables me to be good at a marathon too. I train 50 weeks of the year and that keeps me prepared for whatever distance I want to race…. I am still competing at a very high lever, but as I get older things get harder and I want to retire before I fall apart."
Indeed Tanni retired finally after the Visa Paralympic World Cup in 2007. Her wish is to coach young athletes for Beijing 2008 Olympic Games.
In spite of ups and downs, she never take her fate lying down. In her splendid life, she has won an amazing eleven gold medals, four silvers and one bronze in series of Paralympics- a top lever athletic career covering two decades. She has won the London Wheelchair Marathon six times, more than any other competitor, and she has set over thirty world records.
What advice does she have for young athletes? "Work hard at your studies, and then train, train and train again."
| 1． |
Which of the following sports did Tanni like before thirteen?
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| 2． |
When did Tanni win her first Olympic gold medal?
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| 3． |
The underlined word "that" in the 5th paragraph refers to.
|
| 4． |
What's the right order of the events related to Tanni? a. She works as a coach. b. She took up athletics.
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| 5． |
What can we learn from Tanni's success?
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E
Almost every day we come across situations in which we have to make decisions one way or another. Choice, we are given to believe, is a right. But for a good many people in the world. In rich and poor countries, choice is a luxury, something wonderful but hard to get, not a right. And for those who think they are exercising their right to make choices, the whole system is merely an illusion, a false idea created by companies and advertiser, hoping to sell their products.
The endless choice gives birth to anxiety in people’s lives. Buying something as basic as a coffee pot is not exactly simple. Easy access to a wide range of everyday goods leads to a sense of powerlessness in many people, ending in the shopper giving up and walking away, or just buying an unsuitable item(商品) that is not really wanted. Recent studies in England have shown that many electrical goods bought in almost every family are not really needed. More difficult decision-making is then either avoided or trusted into the hands of the professionals, lifestyle instructors, or advisors.
It is not just the availability of the goods that is the problem, but the speed with which new types of products come on the market. Advances in design and production help quicken the process Products also need to have a short lifespan so that the public can be persuaded to replace them within a short time. The typical example is computers, which are almost out-of-date once they are bought. This indeed makes selection a problem. Gone are the days when one could just walk with case into a shop and buy one thing; no choice, no anxiety. What does the author try to argue in Paragraph 1?
| A．The exercise of rights is a luxury. |
| B．The practice of choice is difficult. |
| C．The right of choice is given but at a price. |
| D．Choice and right exist at the same time. |
Why do more choices of goods give rise to anxiety?
| A．Professionals find it hard to decide on a suitable product. |
| B．People are likely to find themselves overcome by business persuasion. |
| C．Shoppers may find themselves lost in the broad range of items. |
| D．Companies and advertisers are often misleading about the rage of choice. |
By using computers as an example, the author wants to prove that .
| A．advanced products meet the needs of people |
| B．products of the latest design fold the market |
| C．competitions are fierce in high-tech industry |
| D．everyday goods need to be replaced often |
What is this passage mainly about?
| A．The variety of choices in modern society. |
| B．The opinions on people’s right in different countries |
| C．The Problems about the availability of everyday goods. |
| D．The helplessness in purchasing decisions |
D
Seeing a volcano erupt (喷发) is a wonderful experience, and you can really feel the beat by climbing to the summit(山顶) of Pacaya for a close-up view. There are guided tours every day up this highly active volcano from Antigua. Giving travelers a chance to see Mother Nature at her most powerful.
Pacaya is an easy drive from Antigua, a beautiful city with many colorful houses along its old streets that are turned into art-works during its Holy Week festival. No matter when you come to Antigua, you won’t miss the Pacaya-tour companies.
But climbing Pacaya is no easy job: it is 2560 metres high, and reaching the summit takes two to three hours of seemingly one-step-forward and two-step-back movements. As you climb, you hear the dull sounds of eruptions high above. Steaming. Hot remains from recent eruptions begin to line the path as you near the active summit; the McKenney Cone(火山锥). Just as though you were going to walk over to the edge of the cone, the road turns to the left and up to the relative safety of the old, inactive summit.
Many tours are timed so that you arrive at the cone of the volcano is plenty of time for sunset and the full contrast between the erupting red lava(熔岩) and the darkening sky. On a good day the view from the summit is extremely exciting. The active mouth boils, sending red lava over its sides, and once in a while shoots hot streams up to 100 metres into the air. There is a strong bad smell in the air even if you take care to be upwind of the cone. As evening turns deeper into the night. the burning lava quietly falls down tae side of the volcano. For you, too, it is time to get down . What is the main purpose of this passage?
| A．To attract tourists to Pacaya. | B．To describe the beauty of Pacaya. |
| C．To introduce guided tours to Pacaya. | D．To explain the power of nature at Pacaya. |
Antigua is a city .
| A．where people can enjoy cultural festivals | B．where the daring Pacaya tour starts |
| C．that gives a close-up view of Paraya | D．that is famous for its tour companies |
Climbing to the McKenney Cone, people will .
| A．walk directly to the active summit | B．hear the continuous loud noise from above |
| C．make greater efforts than to other summits | |
| D．see a path lined with remains of earlier eruptions |
Many tours are timed for people to .
| A．get down the mountain in time when night falls |
| B．avoid the smell from the upwind direction of the cone |
| C．enjoy the fantastic eruption against the darkening sky |
| D．appreciate the scenery of the 2560-metre-high mountain |
C
Being able to multitask—doing several things at the same time—is considered a welcome skill by most people. But if we consider the situation of the young people aged from eight to eighteen, we should think again.
What we often see nowadays is that young people juggle an ever larger number of electronic devices(电子产品)as they study. While working, they also surf on the Internet, send out emails, answer the telephone and listen to music on their iPods. In a sense, they are spending a significant amount of time in fruitless efforts as they multitask.
Multitasking is even changing the relationship between family members. As young people around them. They can no longer greet family members when they enter the house, nor can they cat at the family table.
Multitasking also affects young people’s performance at university and in the workplace. When asked about their opinion of the effect of modern gadgets(器具)on their performance of tasks, many young people gave a positive response(反应). However, the response from the worlds of education and business was not quite as positive. Educators feel that multitasking by children has a serious effect on later development of study skills. They believe that many college students now need help to improve their study skills. Similarly, employers feel that young people entering the job market need to be taught all over again, as modern gadgets have made it unnecessary for them to learn special skills to do their work.What does the underlined word “juggle” in Paragraph 2 most probably mean?
| A．Want to buy | B．Take the place of. |
| C．Use at the same time | D．Seek for information from. |
In Paragraph 3, the author points out that .
| A．family members do not cat at the family table |
| B．family member do not greet each other |
| C．young people live happily in their families |
| D．young people seldom talk with their family members |
What is the main idea of the last paragraph?
| A．Multitasking is harmful to young people’s development. |
| B．Young people benefit a lot from modern gadgets |
| C．Multitasking is an important skill to young people. |
| D．Young people must learn skills for future jobs. |
The author develops the passage mainly by .
| A．providing typical examples | B．following the natural time order |
| C．comparing opinions from different fields | |
| D．presenting a cause and analyzing its effects |
While all my classmates seen to be crazy about a one-way ticket to Mars(火星), I’d rather say Mars is totally unsuitable for human existence. People won’t have enough food supplies there, and the terrible environment would make it impossible for them to live a long life. Besides, the journey won’t be safe. Can anybody explain to me just why people would go to Mars, never to return?
Steve Minear, UK
Here are the things you can think of: the desire to explore a foreign and unique environment, the excitement of being the first humans to open up a new world, the expectation of fame and glory…For scientists there is another reason. Their observations and research will probably lead to great scientific achievements.
Donal Trollop, Canada
There are already too many people on the Earth. I think that sometime before the end of the century, there will be a human colony(殖民地)on Mars. It will happen when people finally realize that tow-way trips to the red planet Mars are unnecessary. Most of the danger of space Flight is in the launches(发射) and landings. Cutting the trip home would therefore reduce the danger of accidents, save a lot of money, and open the way to building an everlasting human settlement on another world.
Enough supplies can be sent on ahead. And every two years more supplies and more people will needs, and Mars is far more pleasant than the other planets in the outer space.
Paul Davies. USA The main purpose of Steve Minear’s writing is .
| A．to report his classmates’ discussion | B．to invite an answer to his question |
| C．to explain the natural state of Mars | D．to show his agreement on going to Mars |
Which of the following best states Donal Trollop’s idea?
| A．There is a plan to send humans to Mars. |
| B．There are many reasons for going to Mars. |
| C．Scientists become famous by doing research on Mars. |
| D．It is possible to build an Earth-like environment on Mars. |
Paul Davies points out that .
| A．humans need only a one-way ticket to Mars. |
| B．two-way trips to Mars will be made safe soon |
| C．it is easy to reduce the danger and cost of flights to Mars |
| D．it is cheap to build an everlasting human settlement on Mars |
What does Paul Davies think of human existence on Mars?
| A．Humans will have to bring all they need from the Earth. |
| B．Humans will find Mars totally unsuitable for living. |
| C．Humans can produce everything they need. |
| D．Humans can live longer in the colony on Mars |