全国通用2011届高考英语专题复习阅读理解(八)
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If you travel to a new exhibit at the San Francisco Conservatory of Flowers, you will have chances to see some meat-eating plants. Take bladderworts, a kind of such plant, for example. They appear so small and grow in a quiet pond. But these are the fastest-known killers of the plant kingdom, able to capture a small insect in 1/50 of a second using a trap door!
Once the trap door closes on the victim, the enzymes(酶) similar to those in the human stomach slowly digest the insect. When dinner is over, the plant opens the trap door and is ready to trap again.
Meat-eating plants grow mostly in wet areas with soil that doesn’ t offer much food value. In such conditions, these amazing plants have developed insect traps to get their nutritional needs over thousands of years. North America has more such plants than any other continent.
Generally speaking, the traps may have attractive appearance to fool the eye, like pitcher plants, which get their name because they look like beautiful pitchers (a container like a bottle) full of nectar(花蜜).
The Asian pitcher plant, for example, has bright colors and an attractive half-closed lid. Curious insects are tempted to come close and take a sip, and then slide down the slippery (光滑的)slope to their deaths.
Hair-like growths along the pitcher walls ensure that nothing cab escape, and the digestive enzymes can get to work. A tiny insect can be digested in a few hours, but a fly takes a couple of days. |