题目内容
（请给出正确答案）
H5N1 could evolve into a potential pandemic that way, or by recombining with human flu.
A．Y
B．N
C．NG
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The H5N1 strain of avian (5) has killed 60 people (6) 2fib in Vietnam, Thailand, Cambodia and Indonesia, but has rarely been found in birds or humans (7) Asia.
Health officials (8) that HSN1 is infecting migrating birds, which could spread the (9) into Europe. Earlier this year China registered the first outbreak of H5N1 (10) wild birds, some of which (11) to breeding grounds in Siberia. These birds could come (12) contact with others flying to Europe and North America.
Russia's (13) began in the Novosibirsk (14) , about 1,750 miles (15) of Moscow in the Asian part of Russia, early last month, but the veterinary service (16) the virus only last week. Valery Mikheyev, the chief sanitary doctor of Novosibirsk, said that teams had been (17) the (18) birds and supervising the slaughter in13 (19) villages. He said, "The state of (20) of the inhabitants of these areas gives (21) cause for alarm. Up to 6,000 people are being (22) per day.
The virus seems to have (23) only private farms that let (24) mix with wild birds. Further outbreaks were registered in the Omsk and Altai regions, but the strain had (25) to be determined, Russia's Emergency Situations Ministry said.
(86)
Bird Flu
The H5N1 strain of influenza(H5N1 类禽流感)-often referred to as bird flu-was first known to have spread from chickens to humans in 1997. Since 2004 it has attacked Asian poultry farms (家禽饲养所), and had a 7% death rate in the first 70 people who were known to have been infected. Health authorities fear this strain, or its descendents (变种), could cause a fatal new flu with the potential to kill billions.
Flu has been a regular disaster of humanity for thousands of years. The flu viruses are a large family, each possessing a mere 10 genes encoded in RNA (核糖核酸). All of the 16 known groups come first from water birds, especially ducks and gulls (鸥). The virus is well adapted to their immune systems, and does not usually make them very sick. This leaves the animals free to move around and spread the virus.
Violent virus
But every now and then a bird flu virus is transmitted to all animal whose immune system the virus is not adapted to. If the bird flu from a forest bird spreads to chickens, it causes an average disease but can readily change to a more severe strain. Just such a strain of HSN1 flu has hit large chicken farms in East Asia.
The situation is serious because, in 1997, scientists found for the first time that H5 flu is capable of infecting humans. It was found in 18 people, six of whom died. All the poultry in Hong Kong were destroyed to stop the threat. But it continued to circulate, especially in China.
There were further human cases in China in 2003. Then in early 2004 Vietnam (越南) reported widespread poultry outbreaks and some human cases. Cambodia (柬埔寨) and Thailand denied the outbreaks in the beginning but admitted the fact later. So did China.
A mass poultry selection stopped the outbreaks by March 2004, by which time 23 people had died. But the virus went on, most probably in ducks. But scientists think that we should not blame its persistence and spread in the region all on wild birds. The outbreaks started again in summer 2004, and by mid-April 2005 had caused a total of 51 human deaths, all in Thailand and Vietnam.
Making the jump
The two or three flu virus families that have made the jump to humans mostly cause slight disease, because they have adapted to our immune systems. A yearly winter flu suffers most of the world. But it is not totally benign (良性的). About 700,000 people around the world die of it each year, mainly the very old, very young and the weak.
Common flu vaccines(疫苗) are increasing in popularity, although flu evolves so fast that we need new flu vaccines every year. In 2004 an unexpected shortage of vaccine in the US indicated the weakness of the vaccine supply, which is produced by very few manufacturers. As New Scientist predicted, it took great efforts to limit available supplies to those most at risk of serious illness, preventing extra deaths.
But flu is most deadly when it first makes the jump to people because the virus had no opportunity to adapt itself to our immune systems. H5N1 has continued to infect humans as the outbreak in poultry has increased, with an apparently high death rate. It has so far been hard to infect human beings, and has not spread readily between people. If this viral strain should acquire that ability of attacking us, it could become a lethal pandemic (流行性疾病)-the name for a wide-spread disease that spreads worldwide.
Deadly widespread
In 1918, a virulent (有毒菌株) flu strain appeared in humans and killed 50 million people within a few months.
There have also been two less catastrophic(悲惨的) pandemics. The so-called "Asian" flu of 1957 caused between one and four million deaths, while 1968's "Hong Kong" flu with about half the estimated deadliness of the Asian flu--caused one to two million deaths. Both of these were human flu viruses which
A．Y
B．N
C．NG
Computer reconstructions of ancient skulls (头骨) show that our ancestors had ears built like ours as far back as 350,000 years ago. The ears of social mammals(哺乳动物) are typically designed to recognize sounds made by fellow species members. "So, humanlike ears suggest humanlike speech", say researchers from Spain.
Anthropologists(人类学家) don't know for sure when people started talking. To get a better idea, the new study focused on a group of fossils(化石) from a place in Spain called Sima de los Huesos. The fossils belong to a species(人种) called Homo heidelbergensis. Modem people did not evolve from H. heidelbergensis, but an ancient group called Neandertals might have.
Using a computerized scanner(扫描机), the researchers measured ear structures on the remains. Then, they used information about living people to make three-dimensional (三维的)computer models of what the ancient ears looked like. Finally, they measured how sound would pass through the model ears.
The results showed that the ears could handle almost exactly the stone range of sounds that our ears can today. The researchers suggest that hearing and talking developed in a common ancestor shared by both Neandertals and modern people.
Other experts are more skeptical(怀疑的). Some studies have turned up conflicting results about the ears and vocal chords(声带) of Neandertals. And anyway, hearing could have evolved long before talking. The two don't necessarily go together.
If it's true that our ancestors could talk more than 350,000 years ago, that brings up another question. What kinds of things did they talk about？
"Social mammals" in the second paragraph means "______".
A．our ancestors
B．a kind of ancient human tribe
C．Homo heidelbergensis
D．Neandertals
A
H5N1 avian influenza, known commonly as bird flu, has killed at least 15 people across Asia and was confirmed in China on January 27. No human cases have been found in the mainland, but 13 of the country's 31 provinces, autonomous regions, and municipalities (直辖市) have reported the disease in poultry.
The Chinese government has taken measures to prevent and control the disease. Poultry within 3 km of infected farms is to be killed and those within 5 km vaccinated (进行接种疫苗 ). Meanwhile, there will be constant monitoring and daily reports on the disease across the country, and increased production of bird flu vaccines.
Among the Asian countries and regions affected by bird flu in animals, only Vietnam and Thailand have reported human cases. The people infected were reported to have caught the disease from poultry. While the World Health Organization (WHO) said there is "no proof of human-to-human transmission (传播)" of bird flu.
The big fear is that the disease could combine with a human influenza virus (病毒) to create a deadly new disease that will kill millions of people across the globe. Many Asian farmers live closely with their animals and sell live chickens in the market. This greatly increases the possibility of human beings infected with bird flu.
A spokesman of the WHO said that Asian countries affected by bird flu should introduce a more healthy way of raising and selling chickens. And the people there have to completely change their lifestyle. and attitude towards animals. Here are some safety measures for people to stay healthy:
Keep fit and well through regular exercise;
Avoid infected poultry and infected people;
Avoid eating raw or under-done poultry and eggs;
Make sure there is always fresh air in your home;
Cover your mouth and nose when coughing or sneezing;
Wash your hands frequently.
What does the underlined word "poultry" mean？
[A] Wild birds.
[B] Wild animals.
[C] Home-raised birds.
[D] Home-raised animals.
As far as astronomers can determine, the entire universe is built of the same matter. They have no reason to doubt that matter obeys the same laws in every part of the universe. Therefore, it is reasonable to guess that other stars, with their own planets, were born in the same way as our own solar system. What we know of life on earth suggests that life will arise wherever the proper conditions exist.
Life requires the right amount and kind of atmosphere. This eliminates all those planets in the universe that are not about the same size and weight as the earth. A smaller planet would lose its atmosphere, a larger one would hold too much of it.
Life also required a steady supply of heat and light. This eliminates double stars, or stars that flare up suddenly. Only single stars that are steady sources of heat and light like our sun would qualify.
Finally, life could evolve only if the planet is just the right distance from its sun. With a weaker sun than our own, the planet would have to be closer to it. With a stronger sun, it would have to be farther away.
If we suppose that every star in the universe has a family of planets, then how many planets might support life？ First, eliminate those stars that are not like our sun. Next, eliminate most of their planets, they are either too far from or too close to their suns. Then eliminate all those planets which are not the same size and weight as the earth. Finally, remember that the proper conditions do not necessarily mean that life actually does exist on a planet. It may not have begun yet, or it may have already died out.
This process of elimination seems to leave very few planets on which earthlike life might be found. However, even if life could exist on only one planet in a million, there are so many billions of planets that this would still leave a vast number on which life could exist.
Astronomers believe that matter in different parts of the universe ______.
A．has different laws
B．has one common law
C．shares the same laws
D．shares no common law
As far as astronomers can determine, the entire universe is built of the same matter. They have no reason to doubt that matter obeys the same laws in every part of the universe. Therefore, it is reasonable to guess that other stars, with their own planets, were born in the same way as our own solar system. What we know of life on earth suggests that life will arise wherever the proper conditions exist.
Life requires the right amount and kind of atmosphere. This eliminates all those planets in the universe that are not about the same size and weight as the earth. A smaller planet would lose its atmosphere; a larger one would hold too much of it.
Life also requires a steady supply of heat and light. This eliminates double stars, or stars that flare up suddenly. Only single stars that are steady sources of heat and light like our sun would qualify.
Finally, life could evolve only if the planet is just the right distance from its sun. With a weaker sun than our own, the planet would have to be closer to it. With a stronger sun, it would have to be farther away.
If we suppose that every star in the universe has a family of planets, then how many planets might support life？ First, eliminate those stars that are not like our sun. Next eliminate most of their planets; they are either too far from or too close to their suns. Then eliminate all those planets which are not the same size and weight as the earth. Finally, remember that the proper conditions do not necessarily mean that life actually does exist on a planet. It may not have begun yet, or it may have already died out.
This process of elimination seems to leave very few planets on which earthlike life might be found. However, even if life could exist on only one planet in a million, there are so many billions of planets that this would still leave a vast number on which life could exist.
第36题：Astronomers believe that matter in different parts of the universe
A) has different laws.
B) has one common law.
C) shares the same laws
D) shares no common law.
根据短文回答 36～40 题。
Life in the Universe
Many scientists today are convinced that life exists elsewhere in the universe － life probably much like that on our own planet. They reason in the folio, wing way.
As far as astronomers (天文学家) can determine, the entire universe is built of the same matter. They have no reason to doubt that matter obeys the same laws in every part of the universe. Therefore, it is reasonable to guess that other stars, with their own planets, were born in the same way as our own solar system. What we know of life on earth suggests that life will arise wherever the proper conditions exist.
Life requires the right amount and kind of atmosphere. This .eliminates all those planets in the universe that are not about the same size and weight as the earth. A smaller planet would lose its atmosphere; a larger one would hold too much of it.
Life also requires a steady supply of heat and light. This eliminates double stars, or tars that flare up (闪耀) suddenly. Only single stab that are steady sources of heat and light like our sun would qualify.
Finally, life could evolve only if the planet is just the right distance from its sun. With a weaker sun than our own, the planet would have to be closer to it. With a stronger sun, it would have to be farther away.
If we suppose that every star in the universe has a family of planets, then how many planets might support life？ First, eliminate those stars that are not like our sun. Next, eliminate most of their planets; they are either too far from or too close to their suns. Then eliminate all those planets which are not the same size and weight as the earth. Finally, remember that the proper conditions do not necessarily mean that life actually does exist on a planet. It may not have begun yet, or it may have already died out.
This process of elimination seems to leave very few planets on which earthlike life might be found. However, even if life could exist on only one planet in a million, there are so many billions of planets that this would still leave a vast number on which life could exist.
第 36 题 Astronomers believe that matter in different parts of the universe（）
A．obeys different laws
B．obeys one common law
C．obeys the same laws
D．obeys no common law
FDA: Human, Animal Waste Threatens Produce
The biggest food safety risk for fresh fruits and vegetables as they are grown, picked or processed comes from human and animal waste, the US Food and Drug Administration (FDA) said Friday.
More than 9,000 Americans die each year from food-borne diseases and some scientists believe fresh produce is the biggest carrier of contamination.
The FDA issued a set of draft guidelines for US and foreign growers to carefully monitor worker hygiene, water quality, manure management and transportation.
This 34-page draft guidelines urged growers to give workers lessons on basic hygiene such as Using soap to wash their hands, covering wounds that could come into contact with produce, and using only clean toilets.
The FDA guidelines identified "the major source of contamination" for fresh produce as human or animal feces.
"We think just proper controls and proper attention to detail would make a big difference in food safety," said an FDA official. "It is our belief that these guidelines would not be very costly. "
But grower groups disagreed with the FDA's assessment. "Most food-borne disease outbreaks that happen further down the distribution line are due to contamination because people preparing food are not properly washing their hands," said Stacey Zawal, an official with United Fresh Fruit and Vegetable Association. "That is not necessarily true for growers and packers. "
Some US grower organizations have expressed concern that the agency is interfering with on- farm practices. 8 Others object to the FDA's proposal to have growers formally document the picking, handling and transportation of produce so that health officials could quickly recall foods if necessary.
Consumer groups criticized the FDA guidelines as of little use because they will not carry the force of law to But stricter regulations could evolve as researchers find new technology or methods to kill harmful bacteria or parasites, the FDA said.
The FDA recommendations are due to be made final by the FDA later this year for use by US and foreign growers. The matter of encouraging foreign growers to adopt the guidelines remains somewhat tricky but FDA officials say it is vital because of the huge amount of imported produce.
"Food-borne diseases" in this essay means those diseases
A．which people get by eating fruits and vegetables which have been polluted.
B．which people get by eating too many kinds of food.
C．which many kinds of fruit get when polluted by feces.
D．which fruit-growers get by their failure to keep themselves clean.
Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. Their skulls, pelvises, and hind feet are reptilian. The anatomy of their wings suggests that they did not evolve into the class of birds. In pterosaurs a greatly elongated fourth finger of each forelimb supported a wing like membrane. The other fingers were short and reptilian, with sharp claws. In birds the second finger is the principal strut of the wing, which consists primarily of feathers. If the pterosaurs walked on ail fours, the three short fingers may have been employed for grasping. When a pterosaur walked or remained stationary, the fourth finger. and with it the wing, could only turn upward in an extended inverted V-shape along each side of the animal's body.
The pterosaurs resembled both birds and hats in their overall structure and proportions. This is not surprising because the design of any flying vertebrate is subject to aerodynamic constraints. Both the pterosaurs and the birds have hollow bones, a feature that represents a savings in weight. In the birds, however, these bones are reinforced more massively by internal struts.
Although scales typically cover reptiles, the pterosaurs probably had hairy coats. T.H. Huxley reasoned that flying vertebrates must have been warm-blooded because flying implies a high rate of metabolism, which in turn implies a high internal temperature. Huxley speculated that a coat of hair would insulate against loss of body heat and might streamline the body to reduce drag in flight. The recent discovery of a pterosaur specimen covered in long, dense, and relatively thick hair—like fossil material was the first clear evidence that his reasoning was correct.
Efforts to explain how the pterosaurs became airborne have led to suggestions that they launched themselves by jumping from cliffs, by dropping from trees or even by rising into light winds from the surfaces of waves Each hypothesis has its difficulties. The first wrongly assumes that the pterosaurs' hind feet resembled a hat's and could serve as hooks by which the animal could hang in preparation for flight. The second hypothesis seems unlikely because large pterosaurs could not have landed in trees without damaging their wings. The third calls for high waves to channel updrafts. The wind that made such waves however, might have been too strong for the pterosaurs to control their flight once airborne.
It can be inferred from the passage that scientists now generally agree that the ______.
A．enormous wingspans of the pterosaurs enabled them to fly great distances
B．structure of the skeleton of the pterosaurs suggests a close evolutionary relationship to hats
C．fossil remains of the pterosaurs reveal how they solved the problem of powered flight
D．pterosaurs were reptiles
