Robert, an American scientist, has shown that when native grassland areas are invaded 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 grass, so less carbon goes directly into the soil from trees.” said Robert.
In wet areas of the world, the gain from trees absorbing carbon dioxide above ground seems to be outweighed by the loss of carbon from the soil below ground.
Countries that plan to fight against 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.
36.People usually hold the opinion that________.
A.huge dust storms can destroy carbon dioxide
B.planting trees could reduce global warming
C.huge dust storms can destroy the oceans on the Earth
D.planting trees is the only way to control huge dust storms
37.Andy, an environmental scientist, believes that________.
A.environmental problems are more complex than
expected
B.trees shouldn't have been planted in dry places
C.dust plays a more important part than trees
D.carbon dioxide is harmful to everything
【2017届高考英语一轮复习课时作业29:Unit 4《Global warming》(新人教版选修6浙江专用)】相关文章:
★ 【人教版】2014届高考英语一轮复习指导考点针对练:必修4 unit3《A taste of English humour》
★ 【浙江专用】2014届高考英语一轮复习课时作业(三十五)选修7Unit 5《Travelling abroad》
★ 四川省2016届高考英语一轮复习课时作业(37) Module 1 Basketball 外研版选修8
★ 四川省2016届高考英语一轮复习课时作业(44) Module 2 The Renaissance 外研版选修8
★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ规范练:6(含解析)
★ 【北京专用】2014届高考英语一轮复习方案课时作业:必修3 Unit 4 Astronomy:the science of the stars
★ 【人教版】2014届高考英语一轮复习指导考点针对练:选修7 unit4《Sharing》
★ 2014届高考英语一轮复习课时作业(三十)必修5Module 6《Animals in Danger》(外研版)
★ 【人教版】2014届高考英语一轮复习指导考点针对练:必修1 unit4《Earthquakes》
★ 【北京专用】2014届高考英语一轮复习方案课时作业:必修3 Unit 5 Canada
最新
2017-04-24
2017-04-24
2017-04-24
2017-04-24
2017-04-21
2017-04-21