環(huán)球英語 — 791：Disappearing Frogs
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Welcome to Spotlight. I'm Liz Waid.
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And I'm Adam Navis. Spotlight uses a special English method of broadcasting. It is easier for people to understand, no matter where in the world they live.
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It is dark and you cannot see it immediately. But you hear it, so you know it is there. Then you see it. It does not move. It looks just like a rock. You watch as an insect lands on a leaf near it. Then, in a second, the creature's long tongue shoots out of its mouth and sticks to the insect. It pulls the insect back into its mouth. And then, it jumps into the water and swims away. You have just seen a frog eat its dinner. In fact, today's Spotlight is on frogs.
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Frogs are a kind of animal called amphibians. The word "Amphibian" means two lives. The name comes from the fact the most amphibians live part of their life in the water and part on land.
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A female frog will lay eggs in water. When the frogs come out of the eggs they are called tadpoles. At this point, the frog looks like a fish. It has no arms or legs. It uses its tail for swimming. It can even breathe underwater.
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After a time, the frog begins to grow arms and legs. The tail disappears. Then, the frog leaves the water. It spends the rest of its life both on land and in the water. Frogs have powerful back legs. This makes them excellent jumpers and swimmers.
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Frogs are truly amazing creatures. Although they need to live near water, frogs are found all around the world. They can live in different climates - from dry deserts to wet jungles. Some frogs live in trees. Some live under rocks. There are frogs the size of a small coin. Then there are frogs large enough to eat rats, snakes, and small birds. Some frogs even have skin that is full of poison.
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Frogs are also a good sign of the health of an environment. When frogs are healthy, an environment is usually healthy. But when an environment is unhealthy, frogs are often the first to show signs. Their wet skin makes them easily affected by any harmful chemicals.
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Frogs need protection. Losing frogs can throw an environment out of balance. Frogs eat insects. Also, they are themselves food for birds, snakes, and small animals. Chemicals from frogs have been used in treatments for depression, blood flow, and cancer. The Australian red eyed tree frog even provides a medicine that may prevent HIV infection. Frogs are a wonderful part of God's creation.
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The problem is that all around the world, frogs are disappearing. Already, scientists estimate that 165 different kinds of frogs are completely gone. Without help from people, many more kinds of frog will die. Frogs simply cannot reproduce fast enough. It is estimated that without help, another 500 kinds of frogs will disappear.
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Even where frogs are still found, they often have deformities. These changes to their natural bodies include extra legs, missing arms, or misshaped eyes. Reporter Kyla Dunn writes about the situation in the United States:
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"Deformed frogs have been found throughout the United States. One frog had nine legs. Another had an eye growing in its neck. Deformed frogs rarely survive the winter of their first year."
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It is clear that frogs are in trouble. But why are frogs disappearing? What is causing the deformities? While no one knows for sure, there are several leading theories.
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Some people believe frogs are dying because the places they live are changing. Frogs need water to live. When wet lands are filled in for people to build on, frogs are pushed out. They do not have what they need to live.
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Another reason frogs may be disappearing is pollution. Chemicals from factories, farms, and homes enter the water and hurt the frogs. Here again is Kyla Dunn:
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"It appears that chemicals in the water may be to blame. While many frogs are affected, kinds that spend the most time in the water suffer the most. Also, water taken from where deformed frogs live can create deformities in the laboratory. More water leads to more deformities."
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A third reason frogs are dying may be climate change. Warmer temperatures affect the number of insects frogs have for food. The sun's radiation is stronger on a frog's sensitive skin. Warmer temperatures permit less rain. Less rain means less water for frogs to live in. Add all these together and it is a terrible situation for frogs.
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There are other theories about why frogs are disappearing. Some people believe that it is disease. In some areas the case is made that it is a very cold winter. And it is worth noting that some people believe that these missing frogs are nothing to worry about. They think it is only the natural changes that happen in animal populations. However, every day more and more people are beginning to believe that we need to take care of the frogs.
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Some people are already working to save the frogs. Amphibian Ark is one organization trying to protect frogs. It works with zoos around the world to protect frogs that may be threatened. There are over 1200 zoos around the world. These zoos are able to keep and develop healthy frog populations. With over 600,000,000 visitors each year, zoos can educate people about frogs. And one day, local zoos can put local frogs back in local places. The Amphibian Ark's program director Kevin Zippel says:
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"To keep a frog in a zoo, about 50 wild frogs are needed to keep a genetic mixture. You could do it in a small room. For the price to keep a single elephant for a year, you could pay to save a whole kind of frog."
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It may not be easy to protect frogs. It may cost more money than we would like. It will take a lot of hard work. However, if frogs show us the health of the environment we should be careful. Sickness in frogs may give us a good look at our own future. We may be seeing what will happen to us, if we continue to do nothing.
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