题目内容

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.

1.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.

2.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.

3.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

4.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

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Joy in the Journey If you have ever been discouraged because of failure, please read on.For often, achieving what you set out to do is not the important thing.Let me explain.

Two brothers decided to dig a deep hole behind their house.As they were working, a couple of older boys stopped by to .“What are you doing?” asked one of the visitors.“We plan to dig a hole all the way through the !” One of the brothers volunteered .

The older boys began to , telling the younger ones that digging a hole all the way through the earth was .After a long silence, one of the picked up a jar full of spiders, worms and many other kinds of insects.He the lid and showed the wonderful to the scoffing(嘲笑的)visitors.Then he said quietly and , “Even if we don’t dig all the way through the earth, look at what we have found the way!”

Their goal was far too ambitious, but it did cause them to dig.And that is a goal is for — to cause us to move in the we have chosen, in other words, to keep us ! But not every goal will be fully .Not every job will end .Not every hope will come to pass.Not every love will last.Not every dream will be .But when you fall of your aim, perhaps you can say, “Yes, but look at what I found along the way! Look at the wonderful things my life because I tried to do something!” It is in the digging life is lived.And I believe it is the joy in the journey, in the end, that truly

1.A.rest B.work C.watch D.laugh

2.A.house B.earth C.wall D.road

3.A.calmly B.patientiy C.excitedly D.impatiently

4.A.laugh B.think C.stare D.smile

5.A.important B.difficult C.impossible D.interesting

6.A.passers-by B.watchers C.visitors D.diggers

7.A.pulled B.removed C.broke D.pushed

8.A.contents B.scenes C.pictures D.jars

9.A.properly B.confidently C.carefully D.eagerly

10.A.in B.along C.to D.out

11.A.what B.how C.where D.which

12.A.way B.direction C.life D.sight

13.A.thinking B.moving C.digging D.living

14.A.made B.prepared C.kicked D.achieved

15.A.hopelessly B.pleasantly C.surprisingly D.successfully

16.A.come true B.realized C.made D.treasured

17.A.short B.lost C.out D.behind

18.A.breaking into B.turning to C.coming into D.holding to

19.A.when B.where C.which D.that

20.A.matters B.happens C.appears D.exists

Dr. Sylvia Earle wants you to stop eating fish. It's not because fish are endangered, though wild fish stocks in many oceans are very low. It's not because they're bad for you, though fish in many areas are exposed to poisonous substances in the water. It’s because they're smart.

"Fish are sensitive, they have personalities," says the marine biologist. For Earle, eating a fish would be like eating a dog or a cat. "I would never eat anyone I know personally."

There's a lot more to fish than meets the eye: they talk to each other, they like to be touched, and they engage in behavior that can seem very human. They can remember things and learn from experience. Earle and a growing number of animal rights activists see these as strong arguments against eating fish altogether.

The activists also point out that fish feel pain and fish suffer horribly on their way from the sea to the supermarket. "While it may seem conspicuous that fish are able to feel pain, like every other animal, some people think of fish as swimming vegetables," says Dr. Lynne Sneddon. "Really, it's kind of a moral question. Is the enjoyment you get from fishing (or eating fish) more important than the pain of the fish?"

Fishermen and (fried) fish lovers are skeptical. "I've never seen a smart fish," says Marie Swaringen as she finishes off a plate of fish at a Seattle seafood restaurant. "If they were very smart, they wouldn't get caught."

"For years, everyone's been telling us to eat fish because it's so good for us," says another diner. "Now I've got to feel guilty while I'm eating my fish? What are they going to think of next? Don't eat salad because cucumbers have feelings?"

1.According to Dr. Sylvia Earle, he would stop eating fish as a result of the following reasons EXCEPT ___________ .

A.Fish are sensitive and have personalities

B.He knows fish very well

C.Fish are dangerous to eat because the water is polluted

D.Fish are clever

2.Dr.Lynne Sneddon describes the behavior of eating fish in a(n) _______ tone.

A.opposed B.optimistic

C.indifferent D.supportive

3.Which word below can take the place of the underlined word “conspicuous” in Paragraph 4?

A.obvious B.easy

C.impossible D.necessary

4.It can be inferred from the last paragraph that _____________ .

A.Human beings should stop eating fish

B.We would feel guilty if we continued eating fish

C.People eat fish because fish are delicious

D.Cucumber is a kind of vegetable or fruit

5.What was the author’s purpose when writing this passage?

A.To advise people to stop eating fish.

B.To introduce a topic of whether people should eat fish.

C.To advise people not to stop eating fish.

D.To tell us that fish will feel pain when caught and transported.

Are you still troubled by a disease called overactive bladder(膀胱)? Why not try TOVIAZ, a medicine used to treat adults 18 years older facing such a condition?

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1.What is the main purpose of the passage?

A. To present a discovery on a scientific research.

B. To give information about a kind of medicine.

C. To teach patients ways of recovery from illness.

D. To show the importance of taking proper medicine.

2.What can be inferred from the passage?

A. There are only four possible side effects of TOVIAZ.

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C. It’s unwise for people under 18 years old to use TOVIAZ

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A. It’s OK to take it with food or without food.

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