LONDON: What could possibly be wrong with planting trees? The benefits are obvious; they firm the soil, soak up (攝取) extra water and take carbon dioxide (二氧化碳) out of the atmosphere.
However, it now turns out that planting trees could add to global warming.
Tree roots do a great job of keeping soil firmly on the ground and out of the wind’s power. The problem is that some of those dust clouds play an important part in taking in carbon dioxide.
Huge dust storms blow out over the oceans from dry parts of North Africa and central Asia. Tons of dust are lifted and left as a thin film over the ocean surface. The dust fuels oceanic life.
Dust from China is carried east and left in the Pacific Ocean. If a tree-planting programme there is successful and the dust supply reduced, the final result may be that less carbon dioxide gets locked away in the ocean.
Andy Ridgwell, an environmental scientist from the University of East Anglia, has spent the past few years studying dust and says his work “shows clearly the complexity of the system and the importance of not tinkering(粗劣地修補(bǔ)) with it without understanding the results. For this reason the need is to focus(集中) on cutting carbon dioxide giving off rather than monkeying (瞎弄) about with the land surface.”
An American scientist, Robert Jackson, has shown that when native grassland areas are invaded(侵入) by trees, carbon is lost from the soil. “We are studying why the soil carbon disappears, but one theory is that trees do a lot more of their growing above ground compared to grasses, so less carbon goes directly into the soil from trees, ” says Jackson.
In wet areas of the world, the gain from trees absorbing carbon dioxide above ground seems to be outweighed(超過) by the loss of carbon from the soil below ground. Countries that plan to combat global warming by planting trees may have to think again.
Solutions to environmental problems are often more complex than they first appear, and understanding the Earth’s climate is a very great challenge.
【小題1】People usually hold the opinion that_____________.
A.huge dust storms can destroy carbon dioxide |
B.huge dust storms can destroy the oceans on the earth |
C.huge dust storms can’t do anything beneficial for man |
D.planting trees is the only way to control huge dust storms |
A.dust plays a more important part than trees |
B.trees shouldn’t have been planted in dry places |
C.carbon dioxide is harmful to everything on the earth |
D.environmental problems are more complex than expected |
A.grassland areas should be covered by forests |
B.trees hold more carbon than grasses |
C.carbon can turn grass into dust |
D.less carbon can make trees grow faster |
【小題1】C
【小題1】D
【小題1】B
解析【小題1】根據(jù)短文第四五段描述,可知作者認(rèn)為沙塵暴對(duì)人類一點(diǎn)好處都沒有,故選C
【小題1】根據(jù)第六段says his work “shows clearly the complexity of the system and the importance of not tinkering(粗劣地修補(bǔ)) with it without understanding the results.描述,可知環(huán)境問題比預(yù)期的要復(fù)雜的多.故選D
【小題1】根據(jù)倒數(shù)第二段“We are studying why the soil carbon disappears, but one theory is that trees do a lot more of their growing above ground compared to grasses, so less carbon goes directly into the soil from trees, ”描述,可知樹木能比草吸收更多的碳素.故選B
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科目:高中英語 來源:英語教研室 題型:054
1 exposition (展覽)Auckland Museum pays 2 to this great New Zealander, Sir Edmund Hillary: Everest and Beyond Exhibition at the museum until April 25.
Hillary reached Mt Everest’s 3 on May 29, 1953—just in time 4 the Queen’s Conation (加冕典禮).
Now 83 and 5 by New Zealand as its greatest 6 countryman, Sir Edmund, a Knight of the Garter, prefers to be called just 7 Ed. He and his wife June were guests of honor at the exhibition opening in February, coinciding(巧合)with the museum’s 150th birthday.
Visitors are 8 into his adventure—packed and charitable world through a
9 treasure chest of his memorabilia(大事記),from a well-worn passport to the ice
10 he used to climb that mountain.
A Nepalese schoolhouse, kitchen and Buddhist temple have been 11 to show the place he has 12 40 years of his charitable soul and money to 13 the Himalayan Trust, building schools, hospitals and all manner of infrastructure(基礎(chǔ)設(shè)施)in the 14 stricken country.
The exhibition also 15 Ed’s climbs in the Southern Alps, a tractor journey he
16 to the South Pole in 1967 and a trip up the River Ganges by jet boat. 17 the exhibition closes it will go to the United States, to 18 Sir Edmund’s jubilee (50年節(jié))year,
19 a celebratory party in London and a 20 with his Sherpa friends in Kathmandu.
1.A.simple B.large C.detailed D.great
2.A.attention B.respect C.admiration D.honor
3.A.top B.peak C.height D.level
4.A.at B.of C.for D.with
5.A.looked upon B.thought about C.looked up D.thought out
6.A.living B.live C.alive D.lively
7.A.short B.plain C.as D.for
8.A.put B.poured C.led D.drawn
9.A.clear B.dear C.real D.new
10.A.knife B.axe C.fork D.spear
11.A.recreated B.recycled C.recovered D.repaired
12.A.spent B.taken C.devoted D.used
13.A.by B.through C.for D.from
14.A.poverty B.storm C.disaster D.earthquakes
15.A.covers B.shows C.tells D.expresses
16.A.paid B.did C.made D.took
17.A.While B.If C.Since D.When
18.A.sign B.mark C.design D.continue
19.A.beginning with B.joining in C.ending up with D.adding up to
20.A.reunion B.repetition C.review D.recovery
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