首页
登录
职称英语
Scientists have long believed one way to stop the Earth’ s atmosphere from w
Scientists have long believed one way to stop the Earth’ s atmosphere from w
游客
2023-09-03
48
管理
问题
Scientists have long believed one way to stop the Earth’ s atmosphere from warming is by planting more trees. The idea is that more trees will take in or absorb stone of the carbon dioxide in the atmosphere. Carbon dioxide is a gas released by cars, factories and other human activities. The gas traps heat in the Earth’ s atmosphere, which warms tile planet. However, two new studies have found that trees may not be as helpful in reducing carbon dioxide as had been thought.
The first study was done at Duke University in Durham, North Carolina. Researchers pumped extra carbon dioxide into a test area where pine trees were growing. The trees grew thirty -four percent faster during the first three years. However, in time, the trees slowed to about their normal growth rate. The scientists say this is because trees need other nutrients, such as nitrogen.
In the second study, researchers from Duke and Bowdoin College in Brunswick, Maine examined the soil around trees. They discovered that as the leaves broke down into the soil, all the carbon was not trapped in the soil. Much of it was released into the atmosphere as carbon dioxide.
The findings of the two studies were published last month in Nature magazine. They suggest there is limited value in planting trees to reduce the carbon dioxide pollution in the atmosphere.
Forest planting has been a part of negotiations on a world agreement to reduce greenhouse gases that scientists believe cause global warming. The United States, Canada, Japan and some other industrial countries have supported the idea. But this new research suggests the idea is not as effective as environmental activists had thought. Scientist Ram Oren of Duke University led the study on tree growth. He says that earlier estimates on the ability of forests to absorb carbon dioxide were overly hopeful. Some scientists not involved in the studies say the research provides some of the first evidence on how trees react to carbon dioxide. Other scientists say the research disputes a belief among some coal and power companies. The companies say that rising levels of carbon dioxide in the atmosphere will not create harmful global warming. Instead, they say it will increase forests and other plants. [br] What happened to the leaves falling from the trees in the second study?
选项
A、They broke down and the main parts turned into oxygen.
B、They broke down and the carbon content had mainly turned into carbon dioxide.
C、They broke down and the carbon content was mainly absorbed in the soil.
D、They absorbed more carbon dioxide.
答案
B
解析
关键语句:“They discovered that as the leaves broke down into the soil,all the carbon was not trapped in the soil.Much of it was released into the atmosphere as carbon dioxide.”而A,C,D均错误。
转载请注明原文地址:https://tihaiku.com/zcyy/2981969.html
相关试题推荐
[originaltext]Americanscientistsaredevelopingmapsthatcanidentifyare
[originaltext]Americanscientistsaredevelopingmapsthatcanidentifyare
ScientistshavelongbelievedonewaytostoptheEarth’satmospherefromw
ScientistshavelongbelievedonewaytostoptheEarth’satmospherefromw
ScientistshavelongbelievedonewaytostoptheEarth’satmospherefromw
ManyleadingscientistsdownthroughtheyearsfromGalileotoEinsteinhave
ManyleadingscientistsdownthroughtheyearsfromGalileotoEinsteinhave
Scientistshavecomeupwithatheoryforwhytimeflieswhenyonarehaving
Scientistshavecomeupwithatheoryforwhytimeflieswhenyonarehaving
Scientistshavecomeupwithatheoryforwhytimeflieswhenyonarehaving
随机试题
WorldWaterShortageAnewstudywarnsthataboutthirtypercentoftheworld
TowardstheendofThinking,FastandSlow,DanielKahnemanlamentsthathe
[originaltext]Goodmorning,everyone.Today,I’dliketotalkabouttherel
WhywasMarthasohappythismorning?[br][originaltext]W:Morning,dad!M:Ma
[originaltext]MyfriendVernonDavieskeptbirds.Onedayhephonedandtol
将二进制序列1011011表示为十六进制是()。A.B3 B.5B C.
下列关于环境质量单因子指数Pi的说法,正确的是( )。A.Pi<1时为超标
抗血友病球蛋白因子称为A.Ⅻ因子 B.X因子 C.Ⅸ因子 D.Ⅷ因子 E
最能发挥教师在教学中的主导作用的教学组织形式是()。 A.个别教学制 B.班
某施工企业为了支付农民工工资,擅自将租赁的脚手架钢管卖给王某,则下列关于该转让合
最新回复
(
0
)