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
2024-05-14
57
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] Why researchers put trees in extra carbon dioxide in the first study?
选项
A、To learn whether trees can still absorb carbon dioxide under extreme conditions.
B、To get more oxygen from these trees.
C、To evaluate the maximum carbon dioxide that trees can absorb.
D、To see the growth rate of these trees.
答案
D
解析
关键语句:“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.”可以看出是研究生长规律。A,B,C均和本文无关。
转载请注明原文地址:https://tihaiku.com/zcyy/3598234.html
相关试题推荐
[originaltext]Americanscientistsaredevelopingmapsthatcanidentifyare
ScientistshavelongbelievedonewaytostoptheEarth’satmospherefromw
ScientistshavelongbelievedonewaytostoptheEarth’satmospherefromw
ManyleadingscientistsdownthroughtheyearsfromGalileotoEinsteinhave
ManyleadingscientistsdownthroughtheyearsfromGalileotoEinsteinhave
ManyleadingscientistsdownthroughtheyearsfromGalileotoEinsteinhave
Scientistshavecomeupwithatheoryforwhytimeflieswhenyonarehaving
Scientistshavecomeupwithatheoryforwhytimeflieswhenyonarehaving
Scientistshavecomeupwithatheoryforwhytimeflieswhenyonarehaving
Scientistshavecomeupwithatheoryforwhytimeflieswhenyonarehaving
随机试题
Whatdoesthemanaskthewomanfor?[br][originaltext]M:HeyDiane.Wherecan
—Howdoyoudealwiththedisagreementbetweenthecompanyandthecustomers?—T
Mostearthquakesoccurwithintheupper15milesoftheearth’ssurface.But
Today,California’spublicschoolsareadisaster.【C1】______bydysfunctiona
Ω是由曲面z=x2+y2,y=x,y=0,z=1在第一卦限所围成的闭区域,f(x
定子电流中的极品负序分量在空气隙中产生的负序旋转磁场,与正序旋转磁场相同。()
健康管理师在日常工作中贯彻以人为本,以健康为中心的原则,必须做到如下哪几项()A
饮食控制可以治疗的先天性疾病是A.黏多糖增多症 B.肝豆状核变性 C.苯丙酮
根据《票据法》的规定,下列关于汇票提示承兑的表述中,正确的有( )。A.见票后
在设计110kV变电站主接线时,当110kV线路为8回时,宜采用下列哪种接线?(
最新回复
(
0
)