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
A、C-F-C’s are coolants for air-conditioners. B、C-F-C’s arc easy to eliminate. C、Farmers and shippers are usually using methyl br
A、C-F-C’s are coolants for air-conditioners. B、C-F-C’s arc easy to eliminate. C、Farmers and shippers are usually using methyl br
admin
2010-04-30
51
问题
Scientists in the United States have reported some good news about the ozone in the atmosphere. Recent findings suggest that the destruction of ozone by pollution is slowing. Ozone is a form of oxygen. Its presence above Earth protects us from radiation from the sun.
In one study, researchers examined information gathered by NASA space agency satellites and by equipment on Earth and said the atmosphere was losing about eight percent of the ozone layer per ten- year period since the late 1970s. In the last five years, though, that rate of loss has dropped by half. The atmosphere should start to gain ozone before long. A full recovery, however, is about 50 years away, as long as the Montreal Protocol remains in place.
That is an international treaty from 1987 to restore the ozone layer. The treaty restricts the use of a number of chemicals that destroy ozone, like chlorofiuorocarbons, or C-F-C’s. Wide use of C-F-C’s began in the 1930s. They became popular coolants in devices such as refrigerators and air conditioners. C-F-C’s remain in the atmosphere for years.
The Montreal Protocol also restricts the use of methyl bromide, a chemical to kill insects. Farmers and shippers are the main users. Natural sources of methyl bromide include oceans and some plants. Scientists say the bromine gas it produces is 50 times more destructive to ozone than chlorine gas from C-F-C’s.
选项
A、C-F-C’s are coolants for air-conditioners.
B、C-F-C’s arc easy to eliminate.
C、Farmers and shippers are usually using methyl bromide to kill insects.
D、Ozone layer will recover very soon as long as we stop using methyl bromide and C-F-C’s.
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/LWOK777K
0
大学英语六级
相关试题推荐
Forthispart,youareallowed30minutestowriteacompositiononthetopicSuicideonCampus.Youshouldwriteatleast150w
Britain’sdependencyoncertainessentialserviceshasgreatlywidenedandbecomeakeyroleinthecountry’s______.Unionwor
Nodirectrelationshiphasbeenprovenbetweenhighcholesterollevelsandheartattacks.Oldpeopleshouldn’tbothertochange
A、Becauseyoungpeoplecan’trememberthevillages.B、BecausethetwoWorldWarsdestroyedmanyvillages.C、Becausethereareno
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonouschemicalsfor(36)______againstinsects.Butinsectsh
A、Computerbusiness.B、Rulesofselling.C、Thewaywegoshopping.D、Thewaywebuymusic.DWhatisreallychangedbyiPod?
Forthispart,youareallowed30minutestowriteacomplainingletter.Lastweek,youboughtaTV,buttherewassomethingwro
WhatprogresshasAfricancountriesmadeintermsofbusinessreform?Thereductionofthe______canleadtogreatereconomic
A、Lackofappropriateterms.B、Lackofscientificmethods.C、Theirdifferentpersonalities.D、Theirreluctancetothinkinacom
A、Sheisalittletired.B、Sheisgoingtostudyinthelibrary.C、Shewantstolistentothemusic.D、Sheisgoingtomakeare
随机试题
女性,30岁,间断上腹痛3年,疼痛多在餐前,进食后缓解。查体:腹平软,剑下偏右压痛。钡餐造影示十二指肠球变形。最可能的诊断是
A、ThesideeffectsoftheHeimlichmaneuver.B、Thecausesofdeathinchokingcases.C、HowtousetheHeimlichmaneuvertosave
世界卫生组织(WHO)对长寿者年龄划分标准的规定是
属于胆碱能受体是()。
患者,男,40岁。晨起后发现左侧项背牵拉疼痛,头向左侧倾斜,颈项活动受限。求治于针灸,以下哪条经脉不被选用
货物A在2009年的价格为。150元,若通货膨胀率为3.5714%,货物A的时价上涨率为2%,则2010年货物A的实价为()元。
市场采购出口货物报检和检验检疫程序与大货贸易相反。
At(31)whenHarrisonenteredthebarhe(32)itwasemptyexceptforthebarmanwhostood(33)thecounter,lazilypolishingt
Peoplecannotdancewithoutmovingtheirfeet.Beescarrytheirfoodontheirbacks.
•Lookatthetablebelow.Itshowsemploymentbyactivityofeightcountriesintheyearof2001.•Whichactivitydoeseachsent
最新回复
(
0
)