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People used to think that wetlands were wasted land. Developers would drain them with ditches(水沟),fill them in with tons of soil,and build houses,schools,and parking areas on them.Then scientists began to realize the important role wetlands played in the environment.
Wetlands act like giant sponges(海绵) during storms.They soak up extra storm water and afterward release it slowly back into the water cycle.This helps prevent flooding. Towns where people have drained wetlands have found that in a big storm,their streets and homes are often flooded because there are no wetlands to soak up the excess water.
Wetlands also act as giant filters where pollutants are absorbed and dissolved over time.Though wetlands can become polluted from dumping,wastewater,and fertilizer run­off from farm fields,they are able to process some pollutants over time because of all the microorganisms and plants living there.
Wetlands are especially important for providing homes and breeding grounds to millions of birds,fish,and amphibians worldwide. Many wetlands have become national wildlife refuges(避难所),where you can go to take pictures and look at birds and animals.
The Everglades are a huge wetland that once covered more than four million acres of southern Florida. Sometimes called the “river of grass”,the Everglades are a shallow sheet of water that slowly flowed across a grassy plain. In the late 1800s people began draining parts of the Everglades for development. Roads were built and towns sprang up.The Everglades shrank to half its original size. Cities like Miami grew up where once there was a thriving wetland. Sewage and waste from the cities were pumped into the remaining wetlands. Over time scientists began to see the importance of the Everglades. Even with its smaller size,the Everglades filtered the pollutants coming from the cities,absorbing the worst of it like a sewage treatment plant. During storms the Everglades protected the cities from storm surge flooding. They also are just a great place to visit and see wildlife.
【小题1】The first paragraph is intended to tell us________.
A.wasted land used to be wetlands
B.people didn’t know the importance of wetlands before
C.wetlands used to be left undisturbed
D.wetlands can be used for building
【小题2】Why can wetlands be compared to giant sponges?
A.They absorb extra water from storms.
B.They become large or small in size.
C.They absorb pollutants and dissolve them.
D.They are made of soft soil.
【小题3】As for the importance of wetlands,how many aspects are mentioned in the passage?
A.Two.B.Three.C.Four.D.Five.
【小题4】The example of the Everglades is given in the last paragraph to show________.
A.the threat to wetlands
B.the protection of wetlands
C.the development of wetlands
D.the importance of wetlands
【小题5】We can infer from the passage that________.
A.some wetlands can be used to build cities or towns
B.wetlands in the world are disappearing fast
C.wetlands play an important role in the ecosystem
D.wetlands are especially important to wildlife
答案:【小题1】B
【小题2】A
【小题3】B
【小题4】D
【小题5】C
试题分析:文中主要介绍了人们原来认为湿地的荒废无用的,而乱开发,实际湿地却对生态平衡起着重要的作用。
【小题1】推理判断题。文章第一段说明,人们原先认为湿地是荒废的土地,因此在那里乱搭乱建,说明人们原先对湿地的重要性认识不足,故选B。
【小题2】细节理解题。从文章第二段可知,湿地可以像海绵一样,吸收暴风雨中的积水,故选A。
【小题3】细节理解题。从文章第二段到第四段,每段说明湿地重要性的一个方面,故选B。
【小题4】推理判断题。分析文章最后一段,本段通过美国the Everglades的例子说明,由于受到人类活动的影响,湿地面积减少,但仍然发挥着十分重要的作用,强调湿地的重要性,故选D。
【小题5】推理判断题。从文章第二段到第四段,分别说明湿地可以吸收暴风雨中的积水、可以过滤污染物以及为鸟类提供栖息繁衍地,说明湿地对生态系统起着重要的作用,故选C。
考点:环境保护类文章