D The recent, apparently successful, prediction by mathematical models of an app

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D
The recent, apparently successful, prediction by mathematical models of an appearance of El Nino—the warm ocean How that periodically develops along the Pacific coast of South America has excited researchers．Jacob Bjerknes pointed out years ago how winds might create either abnormally warm or abnormally cold water in the eastern equatorial （赤道附近的） Pacific．Nevertheless, before the creation of the models, no one could explain why conditions should regularly change between appearances of the warm El Nino and the so-called anti-El Nino．The answer, at least if the current model that links the behavior of the ocean to that of the atmosphere is correct, is to be found in the ocean．
It has long been known that during an El Nino, two conditions exist: unusually warm water extends along the eastern Pacific and winds blow from the west into the warmer air rising over the warm water in the east．The contribution of the model is to show that the winds of an El Nino, which raise sea level in the east, send a signal to the west lowering sea level at the same time．According to the model, that signal is created as a negative （负的） Rossby wave, a wave of lower sea level, that moves westward parallel to the equator at 25 to 85 kilometers per day．Taking months to move across the Pacific, Rossby waves march to the western boundary of the Pacific basin, which is modeled as a smootli wall but in reality consists of quite irregular island chains．
When the waves meet the western boundary, they are reflected, and the model predicts that Rossby waves will be broken into many coastal Kelvin waves carrying the same negative sea-level signal．These eventually shoot toward the equator, and then head eastward along the equator drove by the earth at a．speed of about．250 kilometers per day．When enough Kelvin waves of adequate amplitude （振幅） arrive from the western Pacific, their negative sea-level signal overcomes the feedback mechanism, raising the sea level, and they begin to drive the system into the opposite cold mode．This produces a gradual change in winds, one that will eventually send positive sea-level Rossby waves westward, waves that will eventually return as cold cycle—ending positive Kelvin waves beginning another warming cycle．
67．What is the passage mainly about?
A．How Rossby waves are found．
B．Where El Nino is formed．
C．What the models predict．
D．How the models work．

68．Where does El Nino often appear?
A．Along the western coast of the

USA .
B．In the Pacific in the south, of the equator．
C．In the Pacific in the north of the equator．
D．Along the southern coast of South America．
69．What is right according to the passage?
A．Rossby waves and Kelvin waves move in opposite directions along the equator．
B．People could explain El Nino before the creation of the mathematical models．
C．Adequate sea-level waves can produce westward positive cold cycle．
D．The speed of Rossby waves is faster than that of Kelvin waves．
70．What does the underlined word "waves" in Paragraph 3 refer to?
A．Kelvin waves． B．Sea-level signals． C．Coastal waves． D．Rossby waves．

答案

67．D 68．B 69．A 70．D

解析

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举一反三

D
Is a recently discovered hormone the reason why folks who lose weight can’t keep it off?
Like millions of other fat people, at 530 inches high, more than 300 pounds, Carnie Wilson was not just fat. After trying all sort of diets that didn’t work,

she has to go to the stomach – bypass surgery (胃部迂回手术), ie, have most of her stomach sewed up, only leaving tiny room to hold several tablespoonfuls at most. Result: she simply couldn’t eat the way she used to. In three years, Wilson is one third of her former weight.
Wilson’s experience is not all that unusual, and while doctors still aren’t exactly sure what is going on, a report in last week’s Journal of Medicine offers an explanation. The loss of appetite in bypass patients may be linked to a recently discovered hormone called ghrelin. Not only that, ghrelin may turn out to be one reason we feel hungry and it’s hare for didters to keep weight off.
Nowadays, researchers are careful to stress only what they know for sure. For the three conclusions, the leading Dr. David of the University of Washington says, “I feel very solid about two of them.” The first is that ghrelin levels in the bloodstream rise significantly before meals and drop afterward. The second conclusion is that ghrelin levels are higher on average in people who have lost weight from dieting.
Dr. David is less sure of the third conclusion, that bypass patients have only a quarter as much ghrelin as most people of normal weight. After all, ghrelin is produced by cells in the stomach. Years ago, leptin, a hormone was found as an appetite suppressant (食物抑制剂). But after years of trying, it had to be given up.
What doctor

s suspect is that both leptin and ghrelin are part of a complex system of brain and body chemicals that govern weight and appetite. That does not mena pharmaceutical (药物的) weight control is forever out of the question. “In the next ten years, we will be able to develop new drugs to help people lose weight healthily and effectively.”
47．What can we learn about ghrelin according to the passage?
A．After meals ghrelin levels are higher in the bloodstream.
B．People who have lost weight have less ghreilin in their body.
C．Without ghrelin, people are really difficult to lose weight.
D．Ghrelin is something produced by cells in the stomach.
48．What is Dr. David not sure?
A．pharmaceutical weight control is impossible.

       B．There is less ghrelin in the bypass patients.
C．new drugs will be developed in 10 years.
D．ghrelin levels are higher in people on diet.
49．In fact, people’s weight and appetite are controlled by
A．ghrelin and leptin                      B．hormone and medicine
C．brain and body chemicals                  D．stomach and food
50．What can we infer from the passage?
A．People with a lower ghrelin level go hungry easily.
B．Doctors managed to use leption to control the appetite.
C．Doctors are optimistic about how to lose weight healthily.
D．The loss of appetite in bypass aptient is linked to leptin

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The sea has always interested man. From it he can get food, minerals, and treasure. For thousands of years, he could sail on it. But he could not go far beneath its surface.
Man wants to explore deep into the sea. However, he is not a fish. He must breathe air, so he can’t stay under the water’s surface for any length of time. To explore deep water, man faces even more dangers and problems.
A diver who wants to stay under water for more than a few minutes must breathe air or a special mixture of gases. He can wear a diving suit and have air pumped to him from above. He can carry a tank of air on his back and breathe through a hose(软管) and a mouthpiece. Water weighs 800 times as much as air. Tons of water pushes against a diver deep in the sea. His body is under great pressure.
When a diver is under great pressure, his blood takes in some of the gases he breathes. As he rises to surface, the water pressure becomes less. If the diver rises too quickly, the gases in his blood form bubbles(气泡). The diver is then suffering from the bends(潜函病). The bends can cause a diver to double up in pain. They can even kill him.
60. On the whole, this text is about _________.
A. special mixtures of gases in deep sea.
B. the problems a diver faces in deep sea.
C. air pressure under the surface of sea water.
D. a kind of illness that man suffers in the sea.
61. The text does not say so, but it makes you think that ____________.
A. deep-sea divers should be in good health.
B. divers explore the deep sea only for treasure.
C. there is a special mixture of gases under the sea.
D. diving under the water too quickly causes a kind of illness.
62. Why does a diver get the bends?
A. The air in his blood is used up.
B. His diving suit weighs too much.
C. He comes to the surface too quickly.
D. He tries to do exercise under the sea.
63. From the text we can learn that _____________.
A. man cannot stay under water for more than a few minutes.
B. the sea began to interest man in the last few years.
C. all divers will get the bends sooner or later.
D. the bends may kill a diver.

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In the future your automobile will run on water instead of gas! You will be able to buy a supercomputer that fits in your pocket! You might even drive a flying car!
For each prediction that has come true today, several others have missed by a mile. Many of these predictions didn’t consider how people would want to use the technology, or if people really needed it in their lives or not. Let’s look at some predictions from the not-too-distant past.
Robot Helpers
Where’s the robot in my kitchen? Nowhere, of course. And he’s probably not coming anytime soon. Robots do exist today, but mostly in factories and other manufacturing environments.
Back in the 1950s, however, people said that by now personal robots would be in most people’s homes.
So why hasn’t it happened? Probably because robots are still too expensive and clumsy. And maybe the idea of robots cooking our dinners and washing our clothes is just too weird. At home we seem to be doing fine without them.
Telephones of Tomorrow
In 1964 an American company introduced the video telephone. They said by the year 2000 most people would have a video phone in their homes. But of course the idea hasn’t caught on yet.
Why? The technology worked fine, but it over—looked something obvious: people’s desire for privacy. Would you want to have a video phone conversation with someone after you just step out of the shower? Probably not---it could be embarrassing! Just because a technology available doesn’t always mean people will want to use it.
And finally, how about that crazy prediction of the flying car? It’s not so crazy anymore! But a flying car remains one of the most fascinating technology ideas to capture our imagination. Keep watching the news, or perhaps the sky outside your window, to see what the future will bring.
64. The whole passage is mainly about ________________.
A. predictions that have come true.
B. predictions that haven’t come true.
C. why predictions don’t come true easily.
D. what technology will bring about.
65. The author of this passage won’t believe that _________________.
A. predictions needn’t consider people’s practical use of technology.
B. the future isn’t always easy to guess.
C. not all past predictions have come true.
D. many of the high—tech things our parents thought we’d be using by now simply never appeared.
66. The underlined word “weird” probably means __________.
A. wonderful B. stupid C. practical D. strange
67. What does the author think of the flying car?
A. It is too difficult to imagine.
B. It is too crazy an idea.
C. It is likely to be made.
D. It is often reported in the news.

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C
Can you train your cat to actually use your toilet? Can you not have to deal with litter boxes any more? Well for many people the answers to these questions are yes．
You may have heard that some people have managed to train their cats to use the human toilet, Well this is correct．One advantage to this is the fact that you no longer have to lug heavy bags of litter home from the supermarket, or worry about cleaning out the dirty litter everyday．
Like any other cat training program, training your cat to use the toilet takes times and patience, you just can put your cat on the toilet and hope that they can use it．
By slowly shaping your cat’s behavior over a couple of weeks, you too can end lugging heavy bags of cat litter home from the supermarket．First, start by slowly moving the litter box closer and closer to the toilet each day, so your cat gets used to being in the bathroom and being around the toilet．
Next, when you have had to litter box next to the toilet for several days, slowly raise the litter box higher and higher each day until it is at the level of the toilet．Then find an insert for the top of the toilet, like a shallow pan that can sit in the rim of the toilet and hold litter．
Once your cat gets used to using this litter pan on top of the toilet for a week or so, try removing the pan and your cat should be able to use the toilet．
Like any cat training program, it takes time and effort on the part of the cat owner to do this．Don’t get frustrated with your cat if she is not learning as fast as you would like, many cats learn at their own pace．With a little effort you too can have a toilet trained cat．
64．The author advises you to train your cat to use a toilet so that may    ．
A．keep the toilet clean
B．keep the cat clean
C．save a lot of trouble
D．save a lot of money
65．According to the passage, cat toilet training is a     process．
A．quick                     B．Complicated            C．difficult           D．gradual
66．When you have managed to get your cat to use the toilet, the litter box    ．
A．is no longer needed                B．is still needed
C．should be kept where it is                 D．should be put back where it was
67．We can see from the passage that“a shallow pan”(in Para 6 )    ．
A．is used instead of the litter box               B．is used to protect the cat
C．helps to raise the litter box             D．helps to clean the toilet

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D
One of the most popular new online games is Second Life．These games are also called MMOs for short．But unlike other MMOs, Second Life is not about winning or losing．Second Life is technically a computer game．But people involved in it do not consider it a game, because the players Create everything．Second Life is more for socializing and creating communities．
Users of Second Life are called residents．To take part, they must create an electronic image of themselves．Some look like humans, while others look like animals．Inside the Second Life world, residents build homes, run business, buy and sell things, work, play, and attend school．They even have relationships and get married．
Second Life was created in 2003 by Linden Lab in San Francisco, California．Linden Lab controls the website where the ever—changing world is being created．There are now about one million people around the world who are active in Second Life．The number has grown quickly since the beginning of the year when there were about one hundred thousand users．
The average age of people involved with Second Life is about thirty．However, Linden Lab recently created Teen Second Life for young users．Second Life has its own economy and its own money called Linden dollars．Millions of dollars are made and spent each month in Second Life．Users can enter Second Life for free．But they must pay for a membership if they want to own land or buy and sell goods and services．
Lately, several major companies have become involved with Second Life．They want to be part of the growing business world that exists within the made—up reality．The car maker Toyota, music producer Sony BMG, and even Reuters news agency are among businesses now existing within Second Life．
68．The best title for the passage may be    ．
A．Popular Computer Games                     B．Users of Second Life
C．Business within Second Life                 D．A Million People Get a Second Life
69．According to the passage, Second Life refers to a new online game    ．
A．about winning or losing
B．in which players can create everything
C．mostly for children
D．designed for only one player role
70．We can see from the passage that the users of the Second Life    ．
A．can’t create the electronic images
B．become humans and animals
C．don’t work or play
D．can even get married
71．It can be inferred from the passage that    ．
A．these major companies want to become the players inside the Second Life world
B．these major companies: want to make profits from Second Life
C．we can’t believe in the made—up reality inside the Second Life world
D．these major companies show no interest in Second Life

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