Even plants can run a fever, especially when theyre under attack by insects ordisease. 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 dont have pest problems.
Even better, Paleys 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 Paleys 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 which he failed to obtain 10 years ago.
26. Plants will emit an increased amount of heat when they are _______
A) sprayed with pesticides B) facing an infrared scanner
C) in poor physical condition D) exposed to excessive sun rays
27. In order to apply pesticide spraying precisely, we can use infrared scanning to
_______.
A) estimate the damage to the crops
B) measure the size of the affected area
C) draw a color-coded map
D) locate the problem area
28. Farmers can save a considerable amount of pesticide by _______.
A) resorting to spot-spraying B) consulting infrared scanning experts
C) transforming poisoned rain D) detecting crop problems at an early stage
29. The application of infrared scanning technology to agriculture met with some
difficulties _______.
A) the lack of official support B) its high cost
C) the lack of financial D) its failure to help increase production
30. Infrared scanning technology may be brought back into operation because of _______.
A) the desire of farmers to improve the quality of their produce.
B) growing concern about the excessive use of pesticides on crops
C) the forceful promotion by the Department of Agriculture
D) full support from agricultural experts
答案与解析：
26.C 27.D 28.A 29.C 30.B
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