Despite the good news, civil engineers aren't resting on their successes. Pinned to their drawing boards are blueprints (蓝图的) 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 designs give buildings brains as well as concrete and steel supports, 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, they would save many lives and would be less likely to be damaged during earthquakes.
21.One reason why the loss of lives in the Los Angeles earthquake was comparatively
low is that _______?
A) new computers had been installed in the buildings.
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) improvements had been made in the construction of buildings and highways
22. The function of the computer mentioned in the passage is to _______.
A) counterbalance an earthquake's action on the building
B) predict the coming of an earthquake with accuracy
C) help strengthen the foundation of the building
D) measure the impact of an earthquake's vibrations
23. 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
24. 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 development of flexible building materials
C) the reduction of the impact of ground vibrations
D) early forecasts of earthquakes
25. 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 building
Questions 26 to 30 are based on the following passage.
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 (红外线) 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(杀虫剂) spraying rather than rain poison on a whole field, which invariably includes plants that don't have pest(害虫) 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 in frared 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 from 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 whi
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