首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Plant Gas Scientists have been studying natural sources of methane(甲烷,沼气) for decades but hadn’t regarded plants as a produc
Plant Gas Scientists have been studying natural sources of methane(甲烷,沼气) for decades but hadn’t regarded plants as a produc
admin
2011-05-18
66
问题
Plant Gas
Scientists have been studying natural sources of methane(甲烷,沼气) for decades but hadn’t regarded plants as a producer, notes Frank Keppler, a geochemist(地球化学家) at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. Now Keppler and his colleagues find that plants, from grasses to trees, may also be sources of the greenhouse gas. This is really surprising, because most scientists assumed that methane production requires an oxygen-free environment.
Previously, researchers had thought that it was impossible for plants to make significant amounts of the gas. They had assumed that microbes(微生物) need to be in environments without oxygen to produce methane. Methane is a greenhouse gas, like carbon dioxide. Gases such as methane and carbon dioxide trap heat in Earth’s atmosphere and contribute to global warming.
In its experiments, Keppler’s team used sealed chambers (室,房间;腔) that contained the same concentration of oxygen that Earth’s atmosphere has. They measured the amounts of methane that were released by both living plants and dried plant material, such as fallen leaves.
With the dried plants, the researchers took measurement at temperatures ranging from 30 degrees Celsius to 70 degrees C. . At 30 degrees C. , they found, a gram of dried plant material released up to 3 nanograms(微克) of methane per hour (One nanogram is a billionth of a gram. ). With every 10-degree rise in temperature, the amount of methane released each hour roughly doubled.
Living plants growing at their normal temperatures released as much as 370 nanograms of methane per gram of plant tissue per hour. Methane emissions tripled ( 增加三倍) when living and dead plant was exposed to sunlight.
Because there was plenty of oxygen available, it’s unlikely that the types of bacteria (bacterium 的复数,细菌) that normally make methane were involved. Experiments on plants that were grown in water rather than soil also resulted in methane emissions. That’s another strong sign that the gas came from the plants and not soil microbes.
The new finding is an "interesting observation, " says Jennifer Y. King, a biogeochemist(生物 地球化学家) at the University of Minnesota in St. Paul. Because some types of soil microbes consume methane, they may prevent plant-produced methane from reaching the atmosphere. Field tests will be needed to assess the plant’s influence, she notes.
What is the beneficial point of some microbes consuming plant-produced methane?
选项
A、Methane becomes less poisonous.
B、Methane is turned into a fertilizer.
C、Less methane reaches the atmosphere.
D、Air becomes cleaner.
答案
C
解析
最后一段的第二句可以找到本题的答案。
转载请注明原文地址:https://kaotiyun.com/show/JuLd777K
本试题收录于:
职称英语理工类A级题库职称英语分类
0
职称英语理工类A级
职称英语
相关试题推荐
WederiveinformationmainlyfromtheInternet.
Aromatherapy(芳香疗法)1Aromatherapyisaformofalternativemedicinewhichisbasedontheuseofveryconcentratedessential
A.toavoidunpleasantthingsinlifeB.inlookingonthebrightsideoflifeC.lesslikelytocatchcoldD.howonelookson
AdaptationofLivingThingsCertainanimalsandplantsdevelopcharacteristicsthathelpthemcopewiththeirenvironmentbe
HypertensionDrugsFoundtoCutRiskofStrokeAustraliandoctorsdeclaredMondaythatacocktailofsimpleantihypertensive
Thiskindofanimalsareonthevergeofextinction,becausesomanyarebeingkilledfortheirfur.
OnBritishNewspapersBesidesthedailynewspapers,thereareanumberofSundaynewspapersinBritain.Manyofthemarecon
TheMagicofSoundMusicisoneofthemostbeautifulformsofartisticexpressionseverinvented.Inmoviesandplays,musi
AthevolunteersdoBbecauseshedoesnothaveaweightproblemCbecausethelifetherecanbeveryboringDmakepeopleovere
FemaleBullfightingItwasaunique,eye-catchingsight:anattractive,womaninashinybullfighter’ssuit,swordinhand,
随机试题
“实现中国梦必须弘扬中国精神。”这里的“中国精神”是指()
男,55岁。双下肢无力半年,右侧明显,近2个月步态不稳,右手不能扣纽扣,无外伤史,无发热。体格检查:颈背部无明显压痛,两上肢前臂、手及上臂尺侧皮肤感觉减退,右侧尤其明显,四肢肌张力增高,肱二头肌反射亢进,双侧膝踝反射亢进,右髌阵挛阳性,右巴宾斯基征阳性。
A、营养输液B、输液剂C、电解质输液D、胶体输液E、脊椎腔注射剂葡萄糖注射液属于
A、芎菊上清丸B、柴胡舒肝丸C、枣仁安神颗粒D、全天麻胶囊E、参茸阿胶失眠,头晕,健忘着宜选用()
在原划拨土地上建造的某办公楼,建成于2001年8月31日,经济寿命为60年,后于2011年8月31日补办了建设用地使用权出让手续,土地使用期限为40年(自2011年8月31日起计),建设用地使用权期间届满后对建筑物按残余价值给予补偿。2012年8月31日对
下列各项不属于《合同法》调整范围的有( )。
某股票的未来股利不变,当股票市价低于股票价值时,则期望报酬率比投资人要求的必要报酬率()。
某商贸公司为增值税一般纳税人,并具有进出口经营权,2005年3月发生相关经营业务如下:(1)从国外进口小轿车1辆,支付买价400000元、相关费用30000元,支付到达我国海关前的运输费用40000元、保险费用20000元。(2)将生产中使用的价值50
Forthispart,youareallowed30minutestowriteanessaybasedonthepicturebelow.Youshouldstartyouressaywithabrief
其他人可能会表现出胃痛或头痛等身体不适的症状。
最新回复
(
0
)