听力原文: Modern zoos are very different from zoos that were built fifty years ago. At that time, zoos were places where people could go to see animals from many parts of the world.
The animals lived in cages that were made of concrete with iron bars, cages that were easy to keep clean. Unfortunately for the animals, the cages were small and impossible to hide in. The zoo environment was anything but natural. Although the zoo keepers took good care of the animals and fed them well, many of the animals did not thrive; they behaved in strange ways, and they often became ill.
In modern zoos, people can see animals in more natural habitats. The animals are given more freedom in large areas so that they can live more as they would in nature. Even the appearance of zoos has changed. Trees and grass grow in the cages, and streams of water flow through the areas that the animals live in. There are few bars; instead, there is often a deep ditch, filled with water, surrounding an area where several species of animals live together as they would naturally.
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A.Animals lived in cages made of concrete with iron bars.
B.Animals lived in natural environments.
C.Streams of water flew through the cages.
D.Several species of animals lived together.
第2题
A.逐步更新.淘汰低效率、能耗大的供用电设备
B.合理选择供用电设备容量.提高设备负荷
C.采用先进设备.提高系统供电的可靠性
D.降低线路损耗.提高供电的功率因数
第7题
为了提高设备的功率因数,可采用措施降低供用电设备消耗的()。
A.有功功率
B.无功功率
C.电压
D.电流
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