题目内容

The “balance of nature”is not an empty phrase. Nature provides a population to occupy a suitable environment and cuts down surplus population to fit the available food supply. One means of reducing surplus population is predators; others are parasitic diseases. Also, population density produces nervous disorders and even drives animals to mass migrations(移民群),like the lemmings of Norway who plunge（冲入）into the sea.

That predatory population increase to control other animals has long been known. Many years ago, the Hudson’s Bay Company records revealed that the fox population went up and down about a year after rabbit population had gone up and down.

Sometimes a situation occurs in which the predatory population is reduced to a level below which nature can readily replace. On Valcour Island in Lake Champlain, a costly campaign resulted in the elimination（消除）of predatory animals only to have birds and small animals increase for four years afterward. Then, lacking predator control, nature resorted to disease to cut down these populations.

Jamaica had an example of nature’s persistence in providing animals for existing habits. Sugar planters, about 75 years ago, imported mongooses（狐猴）to control rats. The mongooses killed off the rats, kids, puppies, and wildlife. Eventually, food became scarce and the mongoose’s population declines.

1. The fact that the number of predators has much to do with that of other animals 　　  .

A. is not recent knowledge　　　　　　　　　　　　　　    B.has just been learned

C.hasn’t been proved yet　　　　　　　　　　　　　　　　　　　　  D.is not important now

2. When predator control fails, nature brings animal population into balance by       .

A. eliminating the number of predators

B.seeking the help of disease to reduce other animals

C.increasing the number of other animals

D.replacing the number of predators immediately

3. When the mongooses killed off the rats they 　　  .

A. became problems themselves　　　　　　　　　　　　 B.ate the sugar crop

C.attacked humans　　　　　　　　　　　　　　　　　　　　   D.had nothing to eat

4. It is implied in this passage that 　　  .

A. sugar planter imported mongooses to control rats

B.man should never kill animals

C.man has complete control over nature

D.to upset the balance of nature can be troublesome

 

答案：A;B;A;D
解析：

1、从文中的“That predatory populations increase to control other animals has long been known”可知答案。

2、从文中第一段的“One means of…；others are parasitic diseases”可知答案。

3、从“Eventually, food became scarce and the mongooses population declines”可知消灭完rats后，mongooses自己也很难再生存下去。

4、A项文中已说出，B、C两项文章中没有任何相关的语句。

 


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【小题1】 A between         B through           C inside                D to
【小题2】A serious          B splendid          C specific          D separate
【小题3】A key              B point             C lead              D center
【小题4】A strict           B different         C typical               D natural
【小题5】A rescue           B prevent              C forbid                D offend
【小题6】A in               B upon              C for               D by
【小题7】A turn             B put               C focus             D carry
【小题8】A over         B along             C with              D beyond
【小题9】A other            B better                C rather                D sooner
【小题10】A conveyed        B consumed          C entered               D exhausted
【小题11】A vital          B initial               C valid             D efficient
【小题12】A disturbed       B depressed         C amazed               D amused
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【小题14】A interfere           B interact            C occupy            D rest
【小题15】A at              B of                    C on                   D within
【小题16】A out             B into              C off              D up
【小题17】A Engage          B Fill              C Involve               D Pack
【小题18】A delete          B escape                C avoid             D spoil
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When an ant dies, other ants move the dead insect out. Sometimes, the dead ant get moved away very soon—within an hour of dying. This behavior is interesting to scientists, who wonder how ants know for sure—and so soon—that another ant is dead.
One scientist recently came up with a way to explain this ant behavior. Dong-Hwan Choe is a biologist. Choe found that Argentine ants have a chemical on the outside of their bodies that signals to other ants, “I’m dead—take me away.”
But there’s a twist to Choe’s discovery. Choe says that the living ants—not just the dead ones —have this death chemical. In other words, while an ant crawls around, perhaps in a picnic or home, it’s telling other ants that it’s dead.
What keeps ants from dragging away the living ants? Choe found that Argentine ants have two additional chemicals on their bodies, and these tell nearby ants something like, “Wait—I’m not dead yet.” So Choe’s research turned up two sets of chemical signals in ants: one says, “I’m dead,” and the other set says, “I’m not dead yet.”
Other scientists have tried to figure out how ants know when another ant is dead. If an ant is knocked unconscious, for example, other ants leave it alone until it wakes up. That means ants know that unmoving ants can still be alive.
Choe suspects that when an Argentine ant dies, the chemical that says “Wait- I’m not dead yet” quickly goes away. Once that chemical is gone, only the one that says “I’m dead” is left. “It’s because the dead ant no longer smells like a living ant that it gets carried to the graveyard, not because its body releases new unique chemicals after death,” said Choe. When other ants detect the “dead” chemical without the “not dead yet” chemical, they drag away the body.
Understanding this behavior may help scientists figure out how to stop Argentine ants from invading new places and causing problems. Choe would like to find a way to use the newly discovered chemicals to spread ant killer to Argentine ant nests.
The ants’ removal behavior is important to the overall health of the nest. “Being able to quickly remove dead individuals and other possible sources of disease is extremely important to all animals living in societies, including us,” says Choe. “Think about all the effort and money that we invest daily in waste management.”
51. The underlined word “twist” in Paragraph 3 means _____.
A. an unexpected change                              B. a clear mistake
C. an important key                                        D. a shocking conclusion
52. Ants judge whether another one is dead or not depending on ______.
A. the sense of taste                                      B. the sense of smell
C. the sense of touch                                               D. the sense of sight
53. The result of the research can be used to ______.
A. kill troublesome pests
B. solve the problem of endangered species
C. prevent further expansion of the ants’ territory
D. keep the balance of nature
54. Why is it important to remove dead individuals?
A. Because it is easier to manage the living.
B. Because it can save money to deal with the waste.
C. Because it can provide more space for the living.
D. Because it can keep the living from suffering disease.
55. What might be the best title of the text?
A. Dead or living? It is easy to judge
B. Pulling away the dead ants is a difficult task
C. Ant nests have great undertaking capacity
D. Leaving it alone or taking it away? Ants feel puzzled


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People also started using herbal(草药的) medicine and by trial and error (反复试验，不断摸索) learned how to cure stomachaches and fevers. They had a witch doctor in the community. He would treat people with simple herbal medicine and magic. Early medicine was practiced the way north tribal Indians did hundreds of years ago and the way some tribes practice it today.
The ancient Chinese believed that the body was ruled by two forces, which they called “yin” and “yang”. The body would become ill if one force overcame the other and the balance between them was changed. Acupuncture (针刺疗法) was the way to bring back the balance between the two.
Also sand painting was an important part of Navaho medicine. The medicine man paints loosely upon the floor of an earth-covered house, where the ceremony takes place, or on a buckskin (鹿皮) or a piece of cloth, by letting the colored sands flow through his fingers with control and skill.
Ancient Mesopotamians believed that diseases come either from an evil spirit or a physical problem, such as worms. The doctor would decide from which source the illness has come from and send the patient either to a herbalist or to a witch doctor.
Egyptians had a very advanced medicine. They would sometimes rely on the god’s power to receive healing, but they also treated illnesses and operated on minor health problems like snake bites. They sucked the blood from the wound and bound the affected limb to stop the poison from spreading.
66. The practice of magic and witchcraft was popular in ancient times because ________ .
A. people could avoid being punished by gods and superior spirits by doing this.
B. people thought they could avoid getting diseases in this way.
C. people believed the evil spirits could be driven away in this way.
D. people often got diseases and this way was very effective.
67. How many places are mentioned where early medicine existed in the passage?
A. Three.     B. Four.      C. Five.      D. Six.
68. From Paragraph 2 we can learn that ________.
A. people can cure lots of diseases by combining herbal medicine and magic.
B. herbal medicine is so effective that it can cure all kinds of diseases.
C. witch doctors treated people only with herbal medicine.
D. people tried lots of times to cure illnesses with herbal medicine.
69. Ancient Chinese people believed that ________.
A. diseases were the result of evil living in human bodies.
B. people would fall ill if the balance in human bodies was disturbed.
C. a medicine man could cure people’s diseases by sand painting.
D. diseases not only came from evil spirits but also were physical problems
70. The passage mainly tells us ________.
A. why ancient people became ill.
B. about the most advanced medicine in ancient times.
C. about the development of herbal medicine.
D. how ancient people cured their diseases.


E
In 1789 the US. government passed a law which said that the land of the American Indians could never be taken from them without their agreement. One hundred years later, however, the Indians only had a very small part of the land that originally belonged to them. How did this great injustice occur?
After 1812 white settlers began to move west across North America. At first, the settlers and the Indians lived in peace. However, the number of settlers increased greatly every year, and slowly the Indians began to see the white settlers as a danger to their survival. To feed themselves, the settlers killed more and more wild animals. The Indians, who depended on these animals for food, had to struggle against starvation. The settlers also brought with them many diseases which were common in white society, but which were new for the Indians. Great numbers of Indians became sick and died. Between 1843 and 1854 the Indian population in one area of the country went down from 100,000 to 30,000.
More land was needed for the increasing number of white settlers. In Washington, the old respect for the rights of the Indians disappeared. The old promises to the Indians were broken; the government began to move groups of Indians from their original homelands to other poorer parts of the country. Some Indians reacted angrily and violently to this treatment. They began to attack white settlers, and the Indian war began. For 30 years, until the late 1880s, different groups of Indians fought against the injustices of the white man. They had a few famous successes, but the result of the struggle was never in doubt. There were too many white soldiers, and they were too powerful. Many Indians were killed; the survivors were moved from their homelands to different areas of the country. It was a terrible chapter in the history of a country that promised freedom and equality to everyone.
72．It can be inferred from the passage that______.
A．in the US there were many laws that provided to the rights of American Indians
B．the law which was passed in 1789 by the US government was not successfully carried out
C．in the 19th century no injustices were done against the Indians by the US government
D．the majority of white settlers were openly opposed to the law passed in 1789
73．According to the passage which of the following is true?
A．The Indians believed that killing too many wild animals had disturbed the balance of nature.
B．The government began to have a better understanding of the Indians in the 1850s.
C．Between 1843 and 1854 about 70,000 Indians were killed in the battle.
D．The whites carried serious diseases into where the Indians lived.
74．It is implied in the passage that______.
A．the Indians had many great successes in the Indians war
B．the Indians had no doubt that they would win the war
C．after the war the Indians stayed where they were before
D．the Indians were too weak to win the struggle
75．The last sentence of the passage______.
A．serves as the author's comment on the historical event described above
B．gives the reader the impression that injustice is everywhere in the US
C．makes a conclusion that such events talked above will never happen again
D．brings about the topic that how the US government will deal with the problem

As a result of pollution, Lake Erie, on the borders of the USA and Canada, is now without many living things.

   Pollution in water is not simply a matter of “poisons” killing large numbers of fish overnight. Very often the effects of pollution are not noticed for many months or years because the first organisms (生物体) to be affected are either plants or plankton (浮游生物). These organisms are the food of fish, birds, and other creatures. When this food disappears, the fish and birds die too. In this way a whole food chain can be wiped out, and it is not until dead fish and water birds are seen at the river’s edge or on the sea shore that people realize what is happening.

   Where do the substances which pollute water come from? There are two main sources, sewage(污水) and industrial waste. As more detergent (洗涤剂)is used in homes, more of it is finally put into our rivers, lakes and seas.  Detergents harm water birds by breaking down the natural substances which keep their feathers waterproof. Sewage itself, if not properly treated, makes the water dirty and prevents all forms of life in rivers and the sea from receiving the oxygen they need. Industrial waste is even more harmful since there are many highly poisonous materials in it, such as copper and lead.

   So if we want to stop this pollution, the answer is simple. Sewage and industrial waste must be made clean before flowing into the water reservoirs. It may already be too late to save some rivers and lakes, but others can still be saved if the correct action is taken at once.

1.Pollution in water is noticed ________.

A. when the first organisms are affected

B. when many fish and birds die   

C. when poisons are poured into water

D. As soon as the balance of nature is destroyed

2.Living things die in a lake or river because there is no ________.

A. water         B. fish                   C. Poison               D. oxygen

3.The underlined word “waterproof” in the third paragraph means “          ”.

A. full of water   B. not allowing water to go through

C. covered with water   D. cleaned by water

4.Which of the following things is /are harmful according to the passage？

A. Industrial waste and chemicals    B. Water in the river

C. Coal and wood  D. plastic

 

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