If you travel to a new exhibition 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 insert. 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 nutrition. 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 continents. 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 full of nectar(花蜜). Hair-like growths along the pitcher walls ensure that nothing can 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. Some of these pitchers are large enough to hold 7.5 liters. Meat-eating plants only eat people in science fiction movies, but sometimes a bird or other small animals will discover that a pitcher plant isn't a good place to get a drink. 小题1:From Paragraph 1，we learn that bladderworts can_ .
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