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阅读下列短文, 从所给的四个选项中, 选出最佳答案。
Bats are the only flying mammals(哺乳动物)in the world. They can't see very well, but they have no trouble flying on the darkest nights and catching the insects (昆虫) that they eat. How do bats manage to fly by radar (雷达)? The bats' radar system (系统) works the same way as the one the ships and planes use, like the radio signals that bounce (反射) back when they hit an object. As a bat flies through the air, he sends out of series (系列) of sounds, thirty to sixty per second. The sound can't be heard by the human ear. If the sounds hit an object, these returned sound signals tell the bat where the object is. The bats' radar system is very good.Tests have been made with bats in a crowded room. Blind in the light, the bats could fly about the room and never touch any object.
(1) This article tells us how _________.
[ ]
A. radar system works
B. bats sent out sound signals
C. sound signals bounce back
D. bats manage to fly and see at night
(2) Bats have no trouble flying on the darkest night because_________.
[ ]
A. they have very poor sight
B. they can catch insects to eat
C. they have a kind of radar system to help them
D. they can see objects in the dark night
(3) As bats fly through the air,_____________.
[ ]
A. they send loud radio signals
B. they hear all kinds of sounds
C. they hit objects and bounce back
D. they send out sound signals
(4) The bat's ears pick up the sounds. This means__________.
[ ]
A. the bat can hear the returned sound signals
B. the bat is unable to hear the sound signals
C. sound signals become stronger when they bounce back
D. sound signals get lost when they bounce back
(5) The bats are completely blind __________.
[ ]
A. in the darkness B. in the light
C. in a crowded room D. at night
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Cloze
Bats are among the least understood creatures in the world today. Until __1__ not many people seemed to care about their rapid disappearance. That's because bats commonly are feared and __2__ . The strong feelings about bats are the result of many false beliefs about the creatures. Stories are told about bats attacking people or __3__ caught in human hair. __4__ , bats are not a threat to people. 5__ , they are central part of the environment(环境). The death of bats severely affects everything that lives in __6__ natural surroundings.
__7__ are one of the most effective controls in insects population. For example, a single little brown bat can catch 600 insects in an hour. “Twenty-five” million bats __8__ lived in a cave in the southwestern state of Arizona, they killed up to 200 tons of insects __9__ night.the bats protected crops of local farms __10__ being destroyed by the insects.
For the past several years, scientists have been learning more about the economical and environmental __11__ of bats. Throughout the world, bats are the main hunters of insects that destroy crops and forests. Bats __12__. help carry pollen(花粉)to fertilize flowers, And they spread plant seeds throughout deserts and forest areas. The loss of bats __13__ many fruits, nuts, and vegetables throughout the world cannot survive.
In the United States, more than, half of the different kinds of bats are considered in __14__ of disappearing. Their loss will increase the dependence of farmers __15__ poisonous chemicals to kill harmful insects.
In 1962, an organization was set up to help __16__ bats and the areas in which they live. The organization is called Bat Conservation International. Meilin Tuttle formed it. He is recognized worldwide __17__ a leading expert on bats. Bats Conservation International now has more than 12,000 members in 55 __18__.
One of the goals of the organization is to educate people about the importance of bats and need to protect __19__. Last June, Bat Conservation International and two American government agencies(组织)announced a joint __20__. They will work together to protect the bats that have made their homes in old mines.