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 (紅外線) 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 (殺蟲劑) spraying rather than rain poison on a whole field, which invariably includes plants that don't have pest (害蟲) 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 a color-code map showing where plants were running" fevers". Farmers could then spot-spray, using 50 to70 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 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 Agricultrue, thinks re- mote 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.
第52題 In order to apply pesticide spraying precisely, we can use infrared scanning to__________.
A.locate the problem areas B.drew a color-ceded map
C.measure the size of the affected area D.estimate the damage to the crops
第53題 Farmers can save a 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
第54題 Plants will emit an increased amount of heat when they are__________.
A.sprayed with pesticides B.in pour physical condition
C.facing an infrared scanner D.exposed to excessive sun rays
第55題 The application of infrared scanning technolgy 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
A.We'll show you our photos when we are back.
B. We are going with our teachers.
C. We are going to Paris.
D. When are you leaving?
E. How long are you going to stay there?
F. Have you been there before?
G. I want to go to London.
H. See you later.
A: Hi, Xiao Wang. Where are you going on vacation?
B: 56 __________.
A: Paris? That sounds great! 57 __________.
B: We are leaving next Tuesday.
A: Who are you going with?
B: 58 __________.
A: 59 __________.
B: For about two weeks. 60__________.
A : Great ! Wish you a pleasant journey!
B: Thanks a lot.