The definition of the standard kilogram is almost entirely wrong. Getting that definition right is a challenge that has tried the patience and intelligence of scientists for decades.
Scientists use just seven basic units to define all the other quantities we use — quantities such as speed or electric power. All of those basic units except the kilogram are themselves defined according to natural properties（属性）that are beyond human control.
For example, the standard second (time) is defined as a specific number of vibration（振动）of a type of radiation sent out by atoms of a special metal. The standard metre (length), in turn, is defined as the length of the path light travels under certain conditions.
Not so the kilogram. This orphan of the basic unit family is simply the mass of a small platinum-iridium alloy cylinder（铂—铱合金筒）locked away in a container maintained by the International Bureau of Weights & Measures in Sevres, France, near Paris. Official bodies around the world have copies of the cylinder.
Embarrassingly, the last time the copies were brought to Sevres for a checkup in the 1980s, officials found that some copies had gained about 20 parts per billion in weight compared to the master cylinder since the previous checkup in the 1940s. This implies that the master cylinder itself may be an inconstant standard.
Several efforts in several different countries are under way to redefine the kilogram according to basic physical quantities such as counting the actual number of atoms of a specific substance in a kilogram or the electromagnetic（电磁的）force that balances a kilogram mass against gravity. A project of the latter type at the laboratories in Gaithersburg, Md., hopes eventually to define mass by means of electrical units.
So far, none of these redefinition projects has borne fruit. They require the very accuracy of measurement and control of experimental conditions. The slightest influence — even a tiny change in weather — can ruin results. You’ve got to hand it to scientists who are willing to devote many years to such painstaking — but extremely important — research.
【小题1】 Compared with other basic units, the kilogram is ____.

A．as accurate as other basic units

B．not universally accepted in the world

C．not defined according to natural properties

D．defined in the same way as other basic units

【小题2】The author introduced the examination of copies of a platinum-iridium alloy cylinder in the 1980s to indicate that ____.

A．the causes of weight changes had been found

B．such kind of checks had been carried out regularly

C．the changes in weight challenged the definition of the kilogram

D．the consequences of such changes were great in research

【小题3】 According to the passage, to define the weight of mass by means of electrical units ____.

A．is the only way to redefine the kilogram scientifically

B．has been accepted as the only possible redefinition project

C．is not as complicated as people understand

D．has been considered by some scientists as a better approach

【小题4】 Which of the following cannot be concluded from the passage?

A．Scientists will achieve success in redefining the kilogram in the near future

B．Some scientists are trying to redefine the kilogram according to basic physical quantities.

C．The redefining of the standard kilogram is quite complicated and can be affected by a number of factors.

D．A number of experiments are being carried out to redefine the kilogram.

For several years, scientists have been testing a substance called interferon(干扰素), a possible wonder drug that is proving to be effective in treating a variety of diseases, including virus infections, bacterial infections, and cancers. To date, the new drug has no side effect of great influence to discourage its use.  But in spite of its success, last year only one gram was produced in the entire world.
The reason for the shortage lies in the structure of interferon. A special protein, the interferon produced from one animal species cannot be used in treating another animal species. In other words, to treat human beings, only interferon produced by human beings may be used. The drug is produced by infecting white blood cells with a virus. Fortunately, it is so effective that the amount given to each patient each time is very small.
Unlike antibiotics (抗生素), interferon does not attack germs directly. Instead, it protects healthy cells from being infected, and prevents the reproduction of viruses within cells.
As you might conclude, one of the most special uses of interferon has been in the treatment of cancer. Dr. Hans Strander, a research physician at Sweden’s famous Karolinska Institute, has treated more than one hundred cancer patients with the new drug. Among a group of selected patients who had received operations for advanced cancer, half were given  traditional treatments and the other half were given interferon. Among those treated with interferon 70 percent of them remained alive over three years, as compared with only 10 to 30 percent among those who had received the traditional treatments.
In the United States, a large-scale project supported by the American Cancer Society is now under way. If the experiment were successful, interferon could become one of the greatest medical discoveries of our time.
【小题1】What is the difference between antibiotics and interferon?

A．Interferon has serious side effects, while antibiotics do not.

B．Antibiotics kill germs by attacking them directly, while interferon does not.

C．Antibiotics are very effective, while the effect of interferon is limited.

D．They are different in structure, although they are both proteins.

【小题2】According to the passage, if 170 cancer patients received interferon treatment, how many of them would remain alive over three years?

A．About 30.

B．About 50.

C．About 120.

D．About 70.

【小题3】The passage tells us that ________.

A．it is difficult to produce interferon in large quantities because of its special structure.

B．interferon is produced widely in lots of countries.

C．few of the patients who had received traditional treatments remained alive.

D．most of the patients who received interferon also needed traditional treatments.

Recently, scientists have developed a wireless brainmachine interface that help restore communication to people who can no longer speak by reading brainwaves using electrodes(电极) stuck on their heads. Unfortunately, these have proved very slow, at roughly one word typed per minute, making normal conversations and social interactions virtually impossible.
Scientist Frank Guenther and his colleagues reveal a brainmachine interface that uses electrodes implanted directly into the brain for research into real time speech.
"It should soon be possible for extremely paralysed individuals who are incapable of speaking to produce speech through a laptop computer, " said Guenther.
The scientists worked with a 26-year- old male volunteer who experience near-total paralysis due to a stroke he suffered when he was 16. They implanted an electrode that had two wires into a part of the brain that help plan and execute movements related to speech. The electrode recorded brain signals when the volunteer attempted to talk and the wires spread them across the scalp(头皮)to help drive a speech synthesizer (合成器). The delay between brain activity and sound output was just 50 milliseconds on average, roughly the same with regular speech.
"He was quite excited, particularly on the first few days we used the system, as he got used to its properties, " Guenther recalled." I am sure the work proceeds slowly from his perspective, as it does from ours. Nonetheless, he was very excited about getting real-time audio feedback of his intended speech and happy to work very hard with us throughout the experiments."
"The current system uses data from just two wires. Within a year it will be possible to implant a system with 16 times as many." Guenther said." This will allow us to tap into neurons(神经元)，which in the end means better control over a synthesizer and thus better speech."
【小题1】In the study of Guenther, electrodes are _______.

A．fixed on the heads	B．put into the heads
C．tied to the heads	D．separated from the heads

【小题2】   The underlined word "them" in Paragraph 4 refers to _______.

A．movements

B．wires

C．brain signals

D．Scientists

【小题3】   What might be the best title for the passage?
A. Wireless Device Are Used to Read Words in the Brain.
B. New Equipment Helps you read others’ mind.
C. Virtual tongue can make you speak fluently.
It is no secret what you are thinking in mind.

  Dolphins and sharks are showing up in surprisingly shallow water just off the Florida coast．Mullets，crabs，rays and small fish gather by the thousands off an Alabama pier．Birds covered in oil are crawling（爬）deep into marshes（沼泽），never to be seen again．
Marine scientists studying the effects of the BP disaster（英国石油公司漏油事件）are seeing some strange phenomena．Fish and other wildlife seem to be fleeing the oil out in the Gulf and gathering in cleaner waters along the coast in a trend that some researchers see as a potentially troubling sign．The animals.presence close to shore means their usual habitat is badly polluted，and the crowding could result in mass die-offs as fish run out of oxygen．Also，the animals could easily be captured by their enemies．
The nearly two-month-old spill（漏油）has created an environmental disaster in US history as tens of millions of gallons have flown into the Gulf of Mexico ecosystem．Scienfists are seeing some unusual things as they try to understand the effects on thousands of species of marine life．For nearly four hours Monday，a three-person crew with Greenpeace cruised（巡航）past delicate islands and mangrove-dotted inlets in Barataria Bay off southern Louisiana．They saw dolphins by the dozen frolicking（嬉戏）in the oily sheen（光泽）and oil-tinged pelicans feeding their young．But they spotted no dead animals．
“I think part of the reason why we’re not seeing more yet is that the impacts of this crisis are really just beginning，”Greenpeace marine biologist John Hocevar said．
The counting of dead wildlife in the Gulf is more than an academic exercise；the deaths will help determine how much BP pays in damages．
【小题1】What do the marine life react to the BP disaster？

A．Dolphins and sharks show up in deep water．

B．Tens of thousands of marine animals are found dead．

C．Sea creatures flee from oil spill，gathering near seashore．

D．Birds crawl（爬）deep into caves．

【小题2】The environmental disaster was caused by       ．

A．the lack of environmental sense of BP

B．the nearly two-mouth-old oil spill

C．the crowding marine life

D．the damage of Mexico Gulf ecosystem

【小题3】What is John Hocevar’s attitude towards the disaster？

A．Disappointed

B．Depressed

C．Neutral

D．Worried

【小题4】From the passage，we can infer that         ．

A．marine scientists have seen some strange phenomena．

B．the disaster has little influence on dolphins．

C．a three-person crew reached no conclusion．

D．BP will pay much money according to the number of dead wildlife there．

A new study warns that about thirty percent of the world's people may not have enough water by the year 2025.
A private American organization called Population Action International did the new study. It says more than three-hundred-thirty-five-million people lack enough water now. The people live in twenty-eight countries. Most of the countries are in Africa or the Middle East.
P-A-I researcher Robert Engelman says by the year 2025, about three-thousand-million people may lack water. At least 18 more countries are expected to have severe water problems. The demand for water keeps increasing. Yet the amount of water on Earth stays the same.
Mr. Engelman says the population in countries that lack water is growing faster than in other parts of the world. He says population growth in these countries will continue to increase.
The report says lack of water in the future may result in several problems. It may increase health problems. Lack of water often means drinking waters are not safe. Mr. Engelman says there are problems all over the world because of diseases, such as cholera, which are carried in water. Lack of water may also result in more international conflict. Countries may have to compete for water in the future. Some countries now get sixty percent of their fresh water from other countries. This is true of Egypt, the Netherlands, Cambodia, Syria, Sudan, and Iraq. And the report says lack of water would affect the ability of developing to improve their economies. This is because new industries often need a large amount of water when they are beginning.
The Population Action International study gives several solutions to the water problem. One way, it says, is to find ways to use water for more than one purpose. Another way is to teach people to be careful not to waste water. A third way is to use less water of agriculture.
The report also says long-term solutions to the water problem must include controls on population growth. It says countries cannot provide clean water unless they slow population growth by limiting the number of children people have.
【小题1】           are expected to have severe water problems by the year 2025.

A．18 countries	B．No countries
C．46 countries	D．28 countries

【小题2】All the following are true except            .

A．New industries need a lot of water

B．There are solutions to the water problem

C．Egypt now has enough fresh water

D．Lack of water may cause conflict between countries

【小题3】It can be learned that          .
A. The ability of developing has nothing to do with lack of water.
B. . It is not known whether diseases have something to do with lack of water
C. Lack of water may also result from international conflict
D There is connection between providing clean water and slowing population growth
【小题4】The best title of the passage would be         .

A．World Water Shortage	B．Population and Water
C．World Conflict	D．Diseases and Water

Thousands of dead red-winged blackbirds fell from the sky in an Arkansas town on New Year’s Eve after massive injuries, tests by Arkansas officials concluded on Monday. Some 5,000 birds mysteriously fell from the sky in Beebe, Arkansas after dark on New Year’s Eve. “The birds suffered from acute physical injuries leading to internal hemorrhage（大量出血） and death. There was no sign of infectious disease,” the Arkansas Game and Fish Commission said in a statement. The birds were otherwise healthy, it said.
One theory is that birds were frightened by New Year's fireworks and flew into buildings or other objects. “Loud noises were reported shortly before the birds began to fall from the sky,” the statement said, adding that blackbirds have poor night vision and seldom fly at night.
　　Another theory was that severe weather such as lightning accounted for the loud noises but this was discounted because the violent weather had already left the area. “We’re leaning more toward a stress event," said Arkansas Game and Fish Commission spokesman Keith Stephens.
The commission also is trying to determine what caused the deaths of up to 100,000 fish over a 20-mile stretch of the Arkansas River near a dam in Ozark, 125 miles west of Beebe. The fish were discovered on December 30. Stephens said the commission expected results on the fish tests in probably a month. Since almost all the fish were one species -- bottom-feeding drum, Stephens said, the test was very important. Stephens also said: “The events do not appear related.” Both that section of the river and the air at the site of the bird deaths were tested for toxins(毒素). Beebe is a town of about 4,500 people located 30 miles northeast of the state capital.
【小题1】What is NOT the probable reason why the dead red-winged blackbirds fell from the sky?

A．Internal hemorrhage	B．Fireworks
C．Lightning weather	D．Murder

【小题2】In the third paragraph, the underlined word discounted probably mean________.

A．not to reduce cost	B．not to believe
C．to make up a part	D．to explain mystery

【小题3】According to Stephens, we can infer the probable cause of the dead fish is _________.[来

A．cold weather	B．poor management
C．disease	D．lack of food

【小题4】The passage is mainly developed by __________.

A．analyzing causes	B．making comparisons
C．examining differences	D．following the time order

   As they migrate（迁移) , butterflies and moths choose the winds they want to fly with, and they change their body positions if they start floating in the wrong direction. This new finding suggests that insects may employ some of the same methods that birds use for traveling long distances. Scientists have long thought that insects were simply at the mercy of the wind.
Fascinating as their skills of flight are, migrating behavior has been difficult to study in insects because many long distant trips happen thousands of feet above ground. Only recently have scientists developed technologies that can detect such little creatures at such great heights.
To their surprise, though, the insects weren't passive travelers on the winds. In autumn, for example, most light winds blew from the east, but the insects somehow sought out ones that carried them south and they positioned themselves to navigate directly to their wintering homes.
Even in the spring, when most winds flowed northward, the insects didn't always go with the flow. If breezes weren't blowing in the exact direction they wanted to go, the insects changed their body positions to compensate. Many migrating birds do the same thing.
The study also found, butterflies and moths actively flew within the air streams that pushed them along. By adding flight speeds to wind speeds, the scientists calculated that butterflies and moths can travel as fast as 100 kilometers an hour. The findings may have real-world applications. With climate warming, migrating insects are growing in number. Knowing how and when these pests move could help when farmers decide when to spray their crops.
【小题1】 What's the main idea of the text?

A．Windsurfing insects have real direction.

B．Wind helps insects greatly in migrating.

C．Insects migrate with the seasons.

D．Scientists have trouble in observing insects.

【小题2】Scientists originally thought that _____.

A．insects were just blown about by the wind

B．insects chose the winds they wanted to ride

C．insects always waited for their favourable winds

D．insects positioned themselves in the winds

【小题3】 It is not easy to study the migrating behavior of the insects because ______.

A．the little creatures can fly very fast

B．their flight is long and high above ground

C．the wind's direction is hard to foresee

D．they have no regular migrating courses

【小题4】 We can learn from the text that _____.

A．insects never position themselves when flying low

B．insects travel more easily in autumn

C．insects fly in the way birds do

D．insects rest a lot when the wind pushes them along

For an owl (猫头鹰) with one-metre wingspan, the sky should be the limit. But Troy prefers his bird’s eye view to be no higher than 5 feet 10 inches. The one-year-old owl has an inconvenient symptom: he’s afraid of heights. After an unfortunate start in life when he fell from his nest by accident, Troy was raised by Gareth Tonen, a handler (饲养员), who just happens to be 5 feet 10 inches tall.
As a result, Troy has grown up without any great ambitions of his own. When it comes to trees, he can’t see what is about and would prefer to fly along at Mr. Tonen’s side. Only when the 25-year-old handler climbs up a tree can Troy be tempted to leave his comfort zone and join him.
Ashley Smith said, “ Troy’s fear of heights was a result of forgetting how to be a bird. He’s been in captivity (被圈养) for as long as he can remember and has never been higher than his handler can lift him. He sees himself as more of a human than an owl, and he doesn’t know how to sit in trees or hunt. Gareth has to almost act like an owl to get Troy to behave like one.”
As a result, a daily tree climb has become part of Troy’s – and Mr. Tonen’s – routine. Ladders have been fixed so Mr. Tonen can climb into the trees and call for Troy, who will fly up and join his handler but go no higher. Most of the time he flies down again, but occasionally Mr. Tonen has to carry him back to ground level. The afternoon ends with a meal of mouse, rabbit or his favorite, chicken.
Mr. Tonen said, “He now looks upon me as his mum or dad. He’s gaining more confidence and if I have to carry on climbing up trees with him then we’ll do what it takes for him to be a high flyer.
【小题1】Troy was brought up by Gareth Tonen because he ______.

A．couldn’t fly high	B．got badly hurt
C．left his parents accidentally	D．couldn’t live in trees

【小题2】 What can you learn from the second paragraph?

A．Troy doesn’t show any interest in flying high up in the sky.

B．Gareth Tonen has spoiled Troy by offering him everything.

C．Gareth Tonen is pleased to see Troy fly along at his side.

D．Troy would like his owner Gareth Tonen to climb up trees.

【小题3】According to Ashley Smith, Troy doesn’t know he is a bird because ______.

A．he has developed the symptom of fearing heights.

B．he has been raised since he was very small.

C．he can’t learn how to fly higher than his owner.

D．he doesn’t want to fly among trees hunting for food.

【小题4】 Why does Gareth Tonen have to climb up trees every day?

A．To set an example of flying high to Troy.

B．To see how high Troy can really fly.

C．To teach Troy how to get meals in high trees.

D．To get Troy back down to cure his fear of heights.

阅读理解D
The deserts of the world are not all covered with sand. Many of them have surfaces of rock or clay(黏土) or small stones. They are not flat, either. They often have high hills and deep valleys. There is some plants’ life in many parts of the desert. There is little rain in the desert, but it does fall often enough for most plants.
The deserts of the world are not uninhabited(无人居住的). People also live outside oases(绿洲), but these people are not farmers. They have camels, goats, donkeys, sheep, etc. These animals can live on the desert plants and do not need much water.
The people of the desert have to move constantly from place to place, they must always look for grass or desert plants for their animals. They usually live in tents. When there is no more food for their animals, they fold up their tents, put them on their camels and donkeys, and move to another place. In good years, when there is enough food for their animals, they trade their skins and their goats and camel hairs with the people of oases for wheat and fruit. But in bad years, when there is not enough food for their animals, the people of the desert would attack the oases people. But they are also hospitable, no man in the desert would ever refuse to give a stranger food and water.
【小题1】According to the passage, deserts are mostly made up of ________.

A．clay

B．rock

C．stones

D．sand

【小题2】The underlined word “hospitable” has the meaning of being ________.

A．kind

B．brave

C．cruel

D．strange

【小题3】 In the desert ________.

A．It rains in spring only.

B．it rains for a short time every month

C．the rainfall is just enough for the plants

D．there is some rain, but far from enough

【小题4】People live ______.

A．only inside the oases	B．both inside and outside the oases
C．only outside the oases	D．in places with regular rainfalls.

阅读理解C
Robots are smart. With their computer brains, they help people work in dangerous places or do difficult jobs. Some robots do regular jobs. Bobby, the mail carrier, brings mail to a large office building in Washington D.C. He is one of the 250 mail carriers in the United States.
Mr. Leachim, who weighs two hundred pounds and is six feet tall, has some advantages as a teacher. One is that he does not forget details. He knows each child’s name, the parents’ names and what each child knows and needs to know. In addition(另外), he knows each child’s pets and hobbies. Mr. Leachim does not make mistakes. Each child goes and tells him his or her name, then dials an identification number. His computer brain puts the child’s voice and number together. He identifies the child without mistakes. Then he starts the lesson.
Another advantage is that Mr. Leachim is flexible. If children need more time to do their lessons, they can move switches. In this way they can repeat Mr. Leachim’s lesson over and over again. When the children do a good job, he tells them something interesting about their hobbies. At the end of the lesson the children switch Mr. Leachim off.
【小题1】The first paragraph of the passage tells us ________.

A．human beings are not as smart as robots

B．robots can help people in many different ways

C．robots will take the place of man to rule the earth

D．we can only use robots to do some regular jobs

【小题2】 Mr. Leachim’s ________ makes him a good teacher.

A．advantages

B．knowledge

C．appearance

D．energy

【小题3】The word “flexible” in the last paragraph means ________.

A．not strict	B．not hard
C．changeable	D．suitable

【小题4】Which of the following statements is TRUE according to the passage?
A. There are 250 robot teachers in the United States.
B. Bobby works in a large office building in Washington D.C.
C. Mr. Leachim is run(开动) and controlled by electricity.
D. The lessons taught by Mr. Leachim are given on a TV set.