题型:阅读理解 题类:常考题 难易度:普通
浙江宁波市九校2019-2020学年高二上学期英语期末考试试卷
Stories and movies often make bats into scary creatures that attack in the dark of night. In real life, however, most bats are harmless. A few are even helpful to humans.
Over 800 species or types of bats feast on troublesome insects that damage crops or spread disease. Another 400 or so bat species eat ripe fruit. These bats are very useful because they pollinate (授粉) flowers and disperse (分散) seeds. There are also a few species of larger bats that hunt small animals like mice, fish, and frogs. A very few even drink blood.
The blood drinkers are the three species of vampire bats. However, the vampire bat doesn't suck blood. Instead, it makes a wound with its sharp teeth and then laps the blood up like a kitty. The animal victim usually sleeps through the entire process. While attacks on humans have occurred, the bats' common targets are livestock and other animals. Interestingly, the vampire bat may become useful to humans. You see, a chemical in the bat's saliva (唾液) thins blood and dissolves blood clots (血栓). Studies indicate this could be a great aid in treating people with strokes. In the future, medicine may be made from vampire bats' saliva.
Some people think bats are birds, but they're not. They have fur, not feathers. And their babies do not hatch from eggs; they're born alive. Also, bats have mouths and noses; birds have beaks. Scientists put them in a special mammal group called Chiroptera.
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