Katey Walter Anthony, a scientist who studies lakes, first visited Alaska’s Lake Esieh in the remote stretch of wilderness. Thousands of lakes dot the region. But Katey Anthony quickly realized this lake was strange. As her boat glided across it, she saw bubbles of all sizes stream up, popping at the surface, and the biggest bubble was as large as a softball. The water seemed to be boiling, but it wasn’t warm. Katey collected some bubbles in a bottle, then she struck a match and opened the bottle to release the gas. The gas caught fire!
The yellow-tipped flame that danced over the bottle confirmed her suspicion. It showed that the lake was giving off a flammable (易燃的）gas called methane. As a powerful greenhouse gas, methane can absorb radiation from the sun, wanning the atmosphere. Methane, along with carbon dioxide, is a major source of global warming. The gas is naturally released as frozen soil, called permafrost, warms up and thaws. And some scientists worry that this methane will cause the world to warm more quickly than they had predicted.
Permafrost covers 22 million square kilometers of territory across the north of Alaska, Canada, Europe and Asia. This frozen soil is rich in organic matter — the remains of plants that lived thousands of years ago. These dead plants froze before they could fully rot. But as that permafrost now melts, single-celled microbes (微生物）have begun dining on those plant remains. They break down the dead stuff into mush, like kitchen scraps in a compost heap (堆肥堆). Along the way, the microbes breathe out methane.
Melting permafrost could release far more methane than scientists had suspected. As permafrost warms up and becomes more like Swiss cheese, it’s logical to think we’re going to see more and more lakes like Lake Esieh. Katey’s discovery at Lake Esieh is really interesting and this lake might turn out to be an unusual event. Methane coming out of a single lake wouldn’t be nearly enough to change the world’s climate. But if other lakes start acting the same way, the matter will be complex.
8. What made Katey Anthony realize Lake Esieh was strange?
A. Its unusual color. B. Its boiling water.
C. Its warm temperature. D. Its giving off bubbles.
9. What did Katey Anthony once probably suspect?
A. Whether the lake released methane.
B. Whether the lake was worth studying.
C. Whether the lake would be easily frozen.
D. Whether the lake could absorb carbon dioxide.
10. What does the underlined word “thaws” in Paragraph 2 probably mean?
A. Becomes unfrozen. B. Becomes unstable.
C. Changes the shape. D. Changes the weight.
11. What does the author mainly talk about in Paragraph 3?
A. Zones of the permafrost. B. The formation of methane.
C. Microbes’ making use of methane.
D. The organic matter in the permafrost.
答案DAAB
The yellow-tipped flame that danced over the bottle confirmed her suspicion. It showed that the lake was giving off a flammable (易燃的）gas called methane. As a powerful greenhouse gas, methane can absorb radiation from the sun, wanning the atmosphere. Methane, along with carbon dioxide, is a major source of global warming. The gas is naturally released as frozen soil, called permafrost, warms up and thaws. And some scientists worry that this methane will cause the world to warm more quickly than they had predicted.
Permafrost covers 22 million square kilometers of territory across the north of Alaska, Canada, Europe and Asia. This frozen soil is rich in organic matter — the remains of plants that lived thousands of years ago. These dead plants froze before they could fully rot. But as that permafrost now melts, single-celled microbes (微生物）have begun dining on those plant remains. They break down the dead stuff into mush, like kitchen scraps in a compost heap (堆肥堆). Along the way, the microbes breathe out methane.
Melting permafrost could release far more methane than scientists had suspected. As permafrost warms up and becomes more like Swiss cheese, it’s logical to think we’re going to see more and more lakes like Lake Esieh. Katey’s discovery at Lake Esieh is really interesting and this lake might turn out to be an unusual event. Methane coming out of a single lake wouldn’t be nearly enough to change the world’s climate. But if other lakes start acting the same way, the matter will be complex.
8. What made Katey Anthony realize Lake Esieh was strange?
A. Its unusual color. B. Its boiling water.
C. Its warm temperature. D. Its giving off bubbles.
9. What did Katey Anthony once probably suspect?
A. Whether the lake released methane.
B. Whether the lake was worth studying.
C. Whether the lake would be easily frozen.
D. Whether the lake could absorb carbon dioxide.
10. What does the underlined word “thaws” in Paragraph 2 probably mean?
A. Becomes unfrozen. B. Becomes unstable.
C. Changes the shape. D. Changes the weight.
11. What does the author mainly talk about in Paragraph 3?
A. Zones of the permafrost. B. The formation of methane.
C. Microbes’ making use of methane.
D. The organic matter in the permafrost.
答案DAAB
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