The Amazon Rainforest: A Natural Treasure Welcome to the Amazon rainforest. As the largest rainfores

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The Amazon Rainforest: A Natural Treasure
Welcome to the Amazon rainforest. As the largest rainforest in the world, it plays a significant role in maintaining the fine balance of the Earth's ecosystem.
The Amazon rainforest crosses into eight countries. With an area of around 5.5 million square kilometres, the Amazon rainforest is more than half the size of China. The Amazon River, from which the rainforest gets its name, is about 6,400 kilometres in length. On its journey from the mountains to the ocean the river supports many different ecosystems. ____44____
Of the 390,000 plant species known to man, more than 40,000 can be found in the Amazon. The forest's different levels support an unbelievable variety of wildlife. At the bottom, there is a system of roots beneath the ground. Above that is the mass of leaf litter on the dark forest floor. ____45____ Then there are the towering ancient hardwoods, and finally the tops of the tallest trees many metres above the ground. Each level of the forest forms its own little world, home to different kinds of living things.
More than 1300 species of birds and over 400 species of mammals hide among the jungle's plant life. This jaguar is one example. It has yellowish-brown coat with black spots. While a significant number of jaguars survive here, they are only one element of this forest's food chain. ____46____ These frogs, in turn, feed on insects which eat leaves and fruit. When a jaguar dies, a tiny army of microorganisms helps break down its body and return the nutrients to the earth.
The Amazon rainforest breathes life into the planet by fixing carbon and producing over 20 percent of all the Earth's oxygen. ____47____ Moreover, the Amazon rainforest is a treasure house of species that can be used for food or medicine. Yet there is one major danger to these irreplaceable plants and animals: us.
____48____ As the impact of human activities such as agriculture and cattle farming continues to grow and the list of species in danger of extinction becomes longer, we are left with a question: can we afford to damage the "lungs of the planet"?
A. They feed on at least 87 species, including frogs.
B. Thus it is often known as the "lungs of the planet".
C. Rivers tend to be the easiest way to enter the forest.
D. The next level is made up of shorter plants with large leaves.
E. They give this area the richest species of plants and animals on the Earth.
F. Currently the trees in the Amazon take in around 500 million tonnes of CO2 each year.
G. Over the past 50 years, 17 percent of the rainforest has disappeared due to human activities.
【答案】44. E    45. D    46. A    47. B    48. G
【解析】