Beyond two or three days, the world’s best weather forecasts are doubtful, and beyond six or seven they are worthless.

The Butterfly Effect is the reason. For small pieces of weather―to a global forecaster, small can mean thunderstorms and blizzards (暴风雪)―any prediction becomes worse rapidly. Errors and uncertainties increase, from dust devils and storms up to continent-size eddies (旋涡) that only satellites can see.

The modern weather models work with net-like points sixty miles apart, and even so, some starting data have to be guessed, since ground stations and satellites cannot see everywhere. But suppose the earth could be covered with sensors placed one foot apart, rising at one-foot intervals all the way to the top of the atmosphere. Suppose every sensor gives perfectly accurate readings of temperature, pressure, humidity (湿度), and any other data a weatherman would want. Exactly at noon a powerful computer takes all the data and calculates what will happen at each point at 12.01, then 12.02, then 12.03… the computer will still be unable to predict whether Princeton will have sun or rain one month away. At noon the spaces between the sensors will hide fluctuations (波动) that the computer will not know about. By 12.01, those fluctuations will already have created small errors one foot away. Soon the errors will have added to the ten-foot scale, and so on up to the size of the globe.

72．A weather forecast ______ in the world.

A．is reliable within one or two days           

B．is doubtful beyond 24 hours

C．becomes useless beyond two or three days                                

D．is still worthwhile in seven days

73．Usually there is a weather sub-station ______.

A．in every city                                         B．every 60 miles

C．between two cities                                D．every one foot

74．Which of the following statements is true?

A．People have not placed sensors one foot apart in the atmosphere.

B．Scientists have already put sensors one foot apart in the world.

C．Every sensor gives perfectly accurate data a weatherman wants.

75．Our computer will not be able to know about fluctuations because ______.

A．the sensors are not good enough           

B．they are hidden by the spaces between the sensors

C．they are too far away                          

D．they move very fast      

Amongst the most popular books being written today are those which are usually classified as science fiction. Hundreds of titles are published every year and are read by all kinds of people. Furthermore, some of the most successful films of recent years have been based on science fiction stories.

　It is often thought that science fiction is a fairly new development in literature, but its ancestors can be found in books written hundreds of years ago. These books were often concerned with the presentation of some form of ideal society, a theme which is still often found in modern stories.

  Most of the classics of science fiction, however, have been written within the last hundred years. Books by writers such as Jules Verne and H.G. Wells, to mention just two well-known authors,

 have been translated into many languages.

 Modern science fiction writers don't write about men from Mars or space adventure stories. They   are more interested in predicting the results of technical developments on society and the human mind; or in imagining future worlds which are a reflection of the world which we live in now.

Because of this their writing has obvious political undertones.

In an age where science fact frequently overtakes science fiction, the writers may find it difficult to keep ahead of scientific advances. Those who are sufficiently clear-sighted to see the way we are going, however, may provide a valuable lesson on how to deal with the problems which society will inevitably face as it tries to master its new technology.

       Biomass energy(生物能), often forgotten as promising alternative to oil, received its day in the sun with the gathering of the Bio-Energy World Congress and Exposition in Atlanta, Georgia, late in April, 2007. Nearly 1700 scientists, businessmen and policy-makers, one-quarter from the foreign nations, gathered for a week to discuss various means of squeezing usable energy out of trees, crops, sea plants and urban waste. Biomass energy in the United States contributes 2.5 percent of the total supply, but this amount can be doubled by 2017 and then doubled again by the year 2027.

  Eight percent of Sweden’s energy supply, for example, is presently coming from wood and pulp(纸浆) remaining. Sweden intends to raise this percentage by more intensive harvesting of waste food lying around in forests, and through the planting of so-called energy forests of fast-growing trees such as willow.

  Brazil is frequently pointed to as a nation with a major successful investment in energy coming from grains: it presently runs 330,000 automobiles on a water and alcohol mixture, replacing 10 percent of its previous oil supply. Brazilian representatives at the conference said they wish to double this in five years, with a final goal of total replacement. Most of the cars are built at the factory to use the mixture, while older models are changed through low-cost government programs.

72.   Which of the following statements is supported by the passage?

     A. Nearly 1700 scientists attended the conference.

     B. A quarter of American businessmen were present at the conference.

     C. Foreign policy-makers accounted for a quarter.

     D. Three-quarters of the representatives were from the U.S.

73.   Of the total supply twenty years later, biomass energy in the U.S. will be      ________.

     A. 5%            B. 10%          C. 15%         D. 20%

74.   Which of the following is NOT regarded as biomass energy?

     A. Willow and sea plants.              B. Wood and grains.

     C. Water and alcohol mixture.        D. Crops and oil mixture.

 75.     A suitable title for this passage would be ____________.

       A. An Energy Conference                     B. Approval of Biomass Energy

       C. Bio-Energy for Automobiles              D. Keys to Energy Crisis

Global warming and changing climatic conditions are triggering disease epidemics in wildlife around the world, reports a famous team of ecologists and epidemiologists in the Friday June 21st issue of Science.

"What is most surprising is the fact that climate sensitive outbreaks are happening with so many different types of pathogens (病原体) ----viruses, bacteria, fungi, and parasites----as well as in such a wide range of hosts (寄主) including corals, oysters, terrestrial plants, birds, and humans, " says lead author Drew Harvell of Cornell University.

"This isn't just a question of coral bleaching for a few marine ecologists, nor just a question of malaria for a few health officials---the number of similar increases in disease incidence is astonishing," says coauthor Richard Ostfeld from the Institute of Ecosystem Studies in Millbrook New York. "We don't want to be alarmists, but we are alarmed."

The team documented examples of viruses, bacteria, and fungi associated with diseases that develop more rapidly with slight rises in temperature. Many vectors of disease such as mosquitoes, flies, and rodents, as well as the viral, fungal, and bacterial pathogens are highly temperature and moisture sensitive. As temperature increases, these carriers are likely to spread into new areas and may have potentially devastating effects on wildlife populations that have not been previously exposed. Reproduction, growth, and biting rates of insects all go up with increases of temperature. Winter is the limiting time for many pathogens, killing back populations each year. With milder winters, this population bottleneck may be removed for many species. Warmer, longer summers also mean that the period of time of disease transmission is longer. Warmer summers may increase host susceptibility to disease due to thermal stress, particularly in the oceans. Marine bacteria and fungal growth rates are positively correlated with increasing temperature.

76．Where can we probably find this passage? In a __________.

A．Book                      B．magazine             C．textbook              D．dictionary

77．According to the passage, the report was written by ________.

A．Drew Harvell                                          B．Richard Ostfeld

C．Drew Harvell and Richard Ostfeld             D．A team of ecologists and epidemiologists

78．What do the underlined words “these carriers” in the last paragraph refer to?

A．Mosquitoes and flies

B．Rodents

C．The viral, fungal, and bacterial pathogens

D．All of the above

79．According to this passage, the outbreaks of disease epidemics tend to occur in ______.

A．winter                   B．spring                 C．summer              D．autumn

Before 1900, many theories existed as to the cause of yellow fever (黄热病). Some doctors were sure the disease was air-borne; others felt that it was spread from person to person. Dr. Carlos Finlay, a well-known Cuban doctor of that time, had long held the theory that it was caused by the bite of mosquitoes. But neither the public nor the doctors then accepted his idea.

  Walter Reed，all American doctor sent to study yellow fever in Cuba，went to talk with Finlay．Reed，after reading a lot on the subject，had begun to think that Dr．Finlay might be fight．Then Reed and his comrades set to work at once．Outside Havana，they set up a laboratory and began experiments to test the theory．The experiments were successful．Now we know：A period of about two weeks must pass before a mosquito，after feeding on a sick person，could infect(传染) another person．The sick person had to have yellow fever a certain number of days before the mosquito biting him was able to carry the disease．

40．Before 1900,many people didn’t think yellow fever was spread_______．

  A．by air

  B．by dirty water

  C．by the bite of certain mosquitoes

  D．by getting in touch with the patient

41．Who first realized the actual cause?

  A．The public．    B．Finlay．    C．Reed．

42．Reed proved the theory_______．

  A．in his American lab

  B．by talking with Finlay

  C．in a kind of scientific Way

  D．by reading a lot of articles

43．One will come down with yellow fever if he has been bitten by_______.

  A．a mosquito

  B．an infected mosquito

  C．a mosquito that has bitten the patient

  D．a mosquito that has bitten the patient for some days

44．What is the possible title for the passage?

  A．Fighting against yellow fever

  B．A doctor against yellow fever

  C．The actual cause of yellow fever

  D．Several theories on yellow fever