Passage 3

　　After the violent earthquake that shook Los Angeles in 1994, earthquake scientists had good news to report: The damage and death toll could have been much worse.

　　More than 60 people died in this earthquake. By comparison earthquake of similar intensity that shook America in 1988 claimed 25,000 victims.

　　Injuries and deaths were relatively less in Los Angeles because the quake occurred at 4:31 a.m. on a holiday, when traffic was light on the city's highways. In addition, changes made to the construction codes in Los Angeles during the last 20 years have strengthened the city's buildings and highways, making them more resistant to quakes.

　　Despite the good news, civil engineers aren't resting on their successes. Pinned to their drawing boards are blue prints for improved quake-resistant buildings. The new designs should offer

　　even greater security to cities where earthquakes often take place.

　　In the past, making structures quake-resistant meant firm yet flexible materials, such as steel and wood, that bend without breaking. Later, people tried to lift a building off its foundation, and insert rubber and steel between the building and its foundation to reduce the impact of ground vibrations. The most recent 5 designs give buildings brains as well as concrete and steel support. Called smart buildings, the structures respond like living organisms to an earthquake’s vibrations. When the ground shakes and the building tips forward, the computer would force the building to shift in the opposite direction.

　　The new smart structures could be very expensive to build. However, that would save many lives and would be less likely to be damaged during earthquakes.

　　41. One reason why the loss of lives in the Los Angeles earthquake was comparatively low is that _______.

　　A. improvements had been made in the construction of buildings and highways

　　B. it occurred in the residential areas rather than on the highways

　　C. large numbers of Los Angeles residents had gone for a holiday

　　D. new computers had been installed in the buildings

　　42. The function of the computer mentioned in the passage is to _______.

　　A. help strengthen the foundation of the building

　　B. predict the coming of an earthquake with accuracy

　　C. counterbalance an earthquake's action on the building

　　D. measure the impact of an earthquake's vibrations

　　43. The smart buildings discussed in the passage _______.

　　A. would cause serious financial problems

　　B. would be worthwhile though costly

　　C. would increase the complexity of architectural design

　　D. can reduce the ground vibrations caused by earthquakes

　　44. It can be inferred from the passage that in minimizing the damage caused by earthquakes attention should be focused on ______.

　　A. the increasing use of rubber and steel in capital construction

　　B. the reduction of the impact of ground vibrations

　　C. the development of flexible building materials

　　D. early forecasts of earthquakes

　　45. The author's main purpose in writing the passage is to ______.

　　A. compare the consequences of the earthquakes that occurred in the U.S.

　　B. encourage civil engineers to make more extensive use of computers

　　C. outline the history of the development of quake-resistant building materials

　　D. report new developments in constructing quake-resistant buildings

　　Passage 4

　　Even plants can run a fever, especially when they're under attack by insects or disease. But unlike humans, plants can have their temperature taken from 3,000 feet away-- straight up. A decade ago,

　　adapting the infrared scanning technology developed for military purposes and other satellites, physicist Stephen Paley came up with a quick way to take the temperature of crops to determine which ones are under stress. The goal was to let farmers precisely target pesticide spraying rather than rain poison on a whole field, which invariably includes plants that don't have pest problems.

　　Even better, Paley's Remote Scanning Services Company could detect crop problems before they became visible to the eye. Mounted on a plane flown at 3,000 feet at night, an infrared scanner measured the heat emitted by crops. The data were transformed into a color-coded map showing where plants were running "fevers". Farmers could then spot-spray, using 50 to 70 percent less pesticide than they otherwise would.

　　The bad news is that Paley's company closed down in 1984, after only three years. Farmers resisted the new technology and long-term backers were hard to find. But with the renewed concern about

　　pesticides on produce, and refinements in infrared scanning, Paley hopes to get back into operation. Agriculture experts have no doubt the technology works. "This technique can be used on 75 percent of agricultural land in the United States," says George Oerther of Texas A&M. Ray Jackson, who recently retired form the Department of .Agriculture, thinks remote infrared crop scanning could be adopted by the end of the decade. But only if Paley finds the financial backing which he failed to obtain 10 years ago.

　　46. Plants will emit an increased amount of heat when they are _____.

　　A. sprayed with pesticides

　　B. in poor physical condition

　　C. facing an infrared scanner

　　D. exposed to excessive sun rays.

　　47. In order to apply pesticide spraying precisely ,we can use infrared scanning to _____.

　　A. locate the problem area

　　B. draw a color-coded map

　　C. measure the size of the affected arm

　　D. estimate the damage to the crops

　　48. Farmers can save considerable amount of pesticide by _______.

　　A. transforming poisoned rain

　　B. consulting infrared scanning experts

　　C. resorting to spot-spraying

　　D. detecting crop problems at an early date

　　49. The application of infrared scanning technology to agriculture met with some difficulties due to ______.

　　A. the lack of official support

　　B. its high cost

　　C. its failure to help increase production

　　D. the lack of financial support

　　50. Infrared scanning technology may be brought back into operation because of _______.

　　A. growing concern about the excessive use of pesticides on crops

　　B. the desire of farmers to improve the quality of their produce

　　C. the forceful promotion by the Department of Agriculture

　　D. full support from agriculture experts

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