Bungee jumping is an activity about jumping from a tall structure while connected to a large elastic cord(有弹性的绳子). The tall structure is usually a fixed object, such as a building, bridge or crane; but it is also possible to jump from a movable object, such as a hot-air balloon or helicopter, that has the ability to stay over one place on the ground; fixed-wing aircraft are unsuitable because they only stay high when moving quickly forward.
When the person jumps, the cord stretches to absorb (吸收)the energy of the fall, then the jumper flies upwards again as the cord jumps back. The jumper oscillates(摆动)up and down until all the energy is used up.
The word bungee first appeared around 1930 and was the name for a rubber eraser. The first modern bungee jumps were made on 1 April 1979 from the 250-foot Clifton Suspension Bridge in Bristol, by David Kirk, Chris Baker and Alan Weston of the Dangerous Sports Club. The jumpers continued with jumps in the US from the Golden Gate and Royal Gorge bridges, spreading the concept worldwide. By 1982 they were jumping from mobile cranes and hot-air balloons. Later they put on commercial(商业的)shows, which began in 1986.
As with any sport, injuries can still happen, and there have been deaths. A relatively common mistake in the cases that may cause death is to use a cord that is too long. The cord should be fully shorter than the height of the jumping place to allow it room to jumper either starts to slow down or keeps speeding up depending upon the speed of falling.Which of the following is NOT suitable for bungee jumping?
| A．The fixed-wing aircraft | B．The helicopter |
| C．The hot-air balloon | D．The mobile crane |
In the second paragraph, the author tells_________________.
| A．who suits bungee jumping |
| B．the principle of bungee jumping |
| C．the material used for bungee jumping |
| D．the danger of bungee jumping |
According to the last paragraph, the safety of the jumpers depends mainly on________.
| A．the weight of the jumper |
| B．the height of the jumping place |
| C．the length of the cord |
| D．the speed of the falling |
The purpose of writing this passage is to__________.
| A．teach people how to carry out a bungee jumping |
| B．remind people of the danger of bungee jumping |
| C．advise people not to take the risk of bungee jumping |
| D．introduce some knowledge about bungee jumping |
With only about 1, 000 pandas left in the world, China is desperately trying to clone(克隆) the animal and save the endangered species(物种). That’s similar to what Texas A＆M University researchers have been undertaking(负责) for the past five years in a project called “Noah’s Ark”.
Noah’s Ark is aimed at collecting eggs, embryos(胚胎), semen and DNA of endangered animals and storing them in liquid nitrogen(氮). If certain species should become extinct, Dr. Duane Kraemer, a professor in Texas A＆M’S College of Veterinary Medicine, says there would be enough of the basic building blocks to reintroduce the species in the future.
It is estimated that as many as 2, 000 species of mammals, birds and reptiles will become extinct in over 100 years. The panda, native only to China, is in danger of becoming extinct in the next 25 years.
Chinese scientists said they grew an embryo introducing cells from a dead female panda into the egg cells of a Japanese white rabbit. They are now trying to implant the embryo into a host animal.
The entire procedure(过程) could take from three to five years to complete.
“The nuclear transfer(核子移植) of one species to another is not easy, and the lack of available(capable of being used) panda eggs could be a major problem,” Kraemer believes. “They will probably have to do several hundred transfers to result in one pregnancy(having a baby). It takes a long time and it’s difficult, but this could be groundbreaking science if it works. They are certainly not putting any live pandas at risk, so it is worth the effort,” adds Kraemer, who is one of the leaders of the Project at Texas A＆M, the first-ever attempt at cloning a dog.
“They are trying to do something that’s never been done, and this is very similar to our work in Noah’s Ark. We’re both trying to save animals that face extinction. I certainly appreciate their effort and there’s a lot we can learn from what they are attempting to do. It’s a research that is very much needed.”
The aim of “Noah’s Ark” project is to_______.
| A．make effort to clone the endangered pandas |
| B．save endangered animals from dying out |
| C．collect DNA of endangered animals to study |
| D．transfer the nuclear of one animal to another |
According to Professor Kraemer, the major problem in cloning pandas would be the lack of _______.
| A．available panda eggs | B．host animals |
| C．qualified researchers | D．enough money |
The best title for the passage may be _______.
| A．China’s Success in Pandas Cloning |
| B．The First Cloned Panda in the World |
| C．Exploring the Possibility to Clone Pandas |
| D．China — the Native Place of Pandas Forever |
From the passage we know that _______.
| A．Kraemer and his team have succeeded in cloning a cat |
| B．scientists try to implant a panda’s egg into a tiger |
| C．Kraemer will work with Chinese scientists in clone researches |
| D．about two thousand of species will probably die out in about a century |
According to a famous optical(光学) expert, Alexander, who recently visited Shanghai, the developed countries in Europe and America have made rules that children must wear resinous(树脂) glasses instead of the traditional glasses made of glass. This is because the glass glasses are more likely to do harm to children’s eyesight.
Alexander pointed out: wearing the right glasses as soon as possible is still the best way to cure and put right children’s eyesight problems.
In America and Japan the resinous glasses have taken up 80 percent of the glasses market. And some European countries and America have made it a law that children, teenagers and drivers must wear resinous glasses. Now, about 10 million children in China have different eyesight problems and they need timely treatment.
But still, too many parents are buying the traditional glass glasses for their children. This is mainly because many parents know little or nothing about the good points of the resinous glasses. Besides, the price for the new glasses is a little higher than the traditional ones. This news article mainly wants to tell us _______.
| A．Alexander visited China and introduced a new type of glasses |
| B．we should wear resinous glasses instead of glass glasses |
| C．resinous glasses are popular in Europe and America |
| D．glasses can be made of other materials instead of glass |
According to Alexander, the “timely treatment” to eyesight problems is _______.
| A．to stop wearing glass glasses any more |
| B．to buy a pair of glasses and wear them right away |
| C．to wear suitable resinous glasses at the right time |
| D．to buy glasses made in Europe, Japan or America if possible |
It can be inferred from this news text that _______.
| A．resinous glasses are not on sale in China yet |
| B．resinous glasses are not acceptable in China |
| C．glass glasses have disappeared on western market because there is a law against them |
| D．glass glasses are the first choice in China not only because of their price |
Zinc(锌) is one of about 20 elements necessary for good health. It is present in the body in a very small amount but makes it possible for important chemical actions to be carried out in cells. Scientists are just beginning to discover how zinc and other elements work.
Researchers first studied zinc as a way to speed recovery. Dr. Waltor Powys formerly with the United States Air Force noted that the laboratory animals recovered faster when some matters were added to their food. One of these matters was zinc. Dr. Powys later tested the zinc treatment on an American airman recovering from medical operations. The airman who received zinc sulphate(硫酸盐) recovered in half of the usual time. Other doctors studied persons who had a number of strange disorders. The doctors learned that all of these problems were caused by lack of zinc in the body. They treated these disorders successfully by giving the patients zinc sulphate.
The amount of zinc in the body can be found by examining blood and hair. A lack of this important element is not uncommon among people in both industrial and developing countries. Zinc is found in most high protein(蛋白质) foods such as meat, milk, fish and eggs. It is also found in whole grains. But many people do not eat enough of these food. Food markets should add these elements so that more people could get needed amount of these necessary matters. Which of the following statements is true?
| A．Scientists found how zinc works a long time ago. |
| B．People need a large amount of zinc to be healthy. |
| C．Zinc allows important chemical actions to take place in cells. |
| D．Zinc must be used in the course of medical operation. |
One of the results from the study of zinc is that _______.
| A．there’s only a little zinc in the human body |
| B．food rich in protein contains more zinc |
| C．some physical problems are caused by lack of zinc |
| D．any patient who receives zinc sulphate gets well immediately |
The best title for the passage may be _______.
| A．A New Discovery | B．Zinc and Health |
| C．How Zinc Works | D．Add Zinc to Your Food |
The common cold is the world's most widespread illness, which is plagues(疫病) that flesh receives.
The most widespread mistake of all is that colds are caused by cold. They are not. They are caused by viruses(病毒) passing on from person to person. You catch a cold by coming into contact, directly or indirectly, with someone who already has one. If cold causes colds, it would be reasonable to expect the Eskimos to suffer from them forever. But they do not. And in isolated Arctic regions explorers have reported being free from colds until coming into contact again with infected people from the outside world by way of packages and mail dropped from airplanes.
During the First World War soldiers who spent long periods in the trenches(战壕), cold and wet, showed no increased tendency to catch colds.
In the Second World War prisoners at the notorious Auschwitz concentration camp(奥斯维辛集中营), naked and starving, were astonished to find that they seldom had colds.
At the Common Cold Research Unit in England, volunteers took part in Experiments in which they gave themselves to the discomforts of being cold and wet for long stretches of time. After taking hot baths, they put on bathing suits, allowed themselves to be with cold water, and then stood about dripping wet in drafty room. Some wore wet socks all day while others exercised in the rain until close to exhaustion. Not one of the volunteers came down with a cold unless a cold virus was actually dropped in his nose.
If, then, cold and wet have nothing to do with catching colds, why are they more frequent in the winter? Despite the most pains—taking research, no one has yet found the answer. One explanation offered by scientists is that people tend to stay together indoors more in cold weather than at other times, and this makes it easier for cold viruses to be passed on.
No one has yet found a cure for the cold. There are drugs and pain suppressors(止痛片) such as aspirin, but all they do is to relieve the symptoms(症状).The writer offered _______ examples to support his argument.
| A．4 | B．5 | C．6 | D．3 |
Which of the following does not agree with the chosen passage?
| A．The Eskimos do not suffer from colds all the time. |
| B．Colds are not caused by cold. |
| C．People suffer from colds just because they like to stay indoors. |
| D．A person may catch a cold by touching someone who already had one. |
Arctic explorers may catch colds when ________.
| A．they are working in the isolated Arctic regions |
| B．they are writing reports in terribly cold weather |
| C．they are free from work in the isolated Arctic regions |
| D．they are coming into touch again with the outside world |
The passage mainly discusses ________.
| A．the experiments on the common cold |
| B．the fallacy about the common cold |
| C．the reason and the way people catch colds |
| D．the continued spread of common colds |
Believe it or not, optical illusion(错觉) can cut highway crashes.
Japan is a case in point. It has reduced automobile crashes on some roads by nearly 75 percent using a simple optical illusion. But stripes, called chevrons(人字形), painted on the roads make drivers think that they are driving faster than they really are, and thus drivers slow down.
Now the American Automobile Association Foundation(基金会) for Traffic Safety in Washington D.C. is planning to repeat Japan’s success. Starting next year, the foundation will paint chevrons and other patterns of stripes on selected roads around the country to test how well the patterns reduce highway crashes.
Excessive (too great) speed plays a major role in as much as one fifth of all fatal traffic accidents, according to the foundation. To help reduce those accidents, the foundation will conduct its tests in areas where speed-related hazards (danger) are the greatest curves, exit slopes, traffic circles, and bridges.
Some studies suggest that straight, horizontal bars painted across roads can initially cut the average speed of drivers in half. However, traffic often returns to full speed within months as drivers become used to seeing the painted bars.
Chevrons, scientists say, not only give drivers the impression that they are driving faster than they really are but also make a lane appear to be narrower. The result is a longer lasting reduction in highway speed and the number of traffic accidents.The passage mainly discusses ________.
| A．a new way of highway speed control |
| B．a new pattern for painting highways |
| C．a new way of training drivers |
| D．a new type of optical illusion |
On roads painted with chevrons, drivers tend to feel that ________.
| A．they should avoid speed-related hazards |
| B．they are driving in the wrong lane |
| C．they should slow down their speed |
| D．they are coming near to the speed limit |
The advantage of chevrons over straight, horizontal bars is that the former ________.
| A．can keep drivers awake | B．can cut road accidents in half |
| C．will look more attractive | D．will have a longer effect on drivers |
The American Automobile Association Foundation for Traffic Safety plans to ________.
| A．try out the Japanese method in certain areas |
| B．change the road signs across the country |
| C．replace straight, horizontal bars with chevrons |
| D．repeat the Japanese road patterns |
What does the author say about straight, horizontal bars painted across roads?
| A．They are suitable only on broad roads. |
| B．They are falling out of use in the United States. |
| C．They are ignored in a long period of time. |
| D．They cannot be used successfully to traffic circles. |
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