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 p
A. estimate the damage to the crops
B. draw a color-coded map
C. measure the size of the affected area
D. locate the problem area
Some people have very good memories and can easily learn quite a long paragraph by heart. But they often forget them almost as quickly as they learn them. There are other people who can only remember things when they have said them over and over, but when they do know them they don’t forget them.
The human mind is rather like a camera, but it takes photographs not only of what we see but of what we feel, hear or smell. There is much to do before the photograph is finished and ready to show to our friends. In the same way, there is much work to be done before we can make a picture remain forever in the mind.
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