题目内容
16.Scientists from the University of East Anglia have identified four new man-made gases that are contributing to the damage to the ozone(臭氧) layer.Two of the gases are accumulating at a rate that is causing concern among researchers.Worries over the growing ozone hole have seen the production of chlorofluorocarbon (CFC) gases restricted since the mid 1980s.But the precise origin of these new,similar substances remains a mystery.
Lying in the atmosphere,the ozone layer plays a critical role in blocking harmful UV rays,which cause cancers in humans and reproductive problems in animals.
Scientists from the British Antarctic Survey were the first to discover a huge"hole"in the ozone over Antarctica in 1985.The evidence quickly pointed to CFC gases,which were invented in the 1920s,and were widely used in refrigeration.Extraordinarily,global action was rapidly agreed to deal with CFCs and the Montreal Protocol to limit these substances came into being in 1987.A total global ban on production came into force in 2010.
Now,the newly discovered four new gases can destroy ozone and are getting into the atmosphere from as yet unidentified sources.Three of the gases are CFCs and one is a hydrochlorofluorocarbon (HCFC),which can also damage ozone.
The research has shown that four gases were not around in the atmosphere at all until the 1960s,which suggests they are man-made.The scientists discovered the gases by analyzing polar snow pack.Air from this snow is a natural archive of what was in the atmosphere up to 100years ago.The researchers also looked at modern air samples,collected at remote Cape Grim in Tasmania.
They estimate that about 74,000tonnes of these gases have been released into the atmosphere.Two of the gases are accumulating at significant rates.However,they don't know where the new gases are being released from and this should be investigated.Possible sources include chemicals for insecticide(杀虫剂) production and solvents(溶液) for cleaning electronic ponents.The three CFCs are being destroyed very slowly in the atmosphere-so even if emissions(散发) were to stop immediately,they will still be around for many decades to come.
Of the four species identified,CFC-113a seems the most worrying as there is a very small but growing emission source somewhere,maybe from agricultural insecticides.We should find it and take it out of production.
63.What do we know about the newly discovered gases?B
A.Some are surely produced by the development of agriculture.
B.The CFCs will have a long impact once they are released.
C.They gather together in the atmosphere at a medium speed.
D.Their amounts are not large enough to cause damage to us.
64.The underlined word"archive"in Paragraph 6is closest to the meaning of"D"
A.state B.resource C.phenomenon D.storeroom
65.What will the scientists probably attempt to do about the gases next?C
A.Find out what can replace things like insecticides and put them into use.
B.Find out how they destroy ozone and get rid of those in the atmosphere.
C.Find out where they are exactly from and stop them from being released.
D.Find out if HCFC is more harmful than CFCs and take proper measures.
分析 本文是一个科学研究类阅读.作者通过这篇文章向我们讲述的是科学家在研究中发现,有四种最主要的人造气体释放的时候会破坏臭氧层.但是至今科学家们还不知道这些气体是来自于哪里.
解答 63.B 推理判断题.根据第四段"The evidence quickly pointed to CFC gases,which were invented in the 1920s,and were widely used in refrigeration.Extraordinarily,global action was rapidly agreed to deal with CFCs and the Montreal Protocol to limit these substances came into being in 1987.A total global ban on production came into force in 2010."可知CFCs一旦释放出来就会产生很长时间的影响,故选B.
64.D 词义猜测题.根据第六段划线后Air from this snow is a natural archive of what was in the atmosphere up to 100years ago.The researchers also looked at modern air samples,collected at remote Cape Grim in Tasmania.可知这是长达一百年的天然储藏室,由此推测出这个单词指的是储藏室,故选D.
65.C 推理判断题,根据倒数第二段"However,they don't know where the new gases are being released from and this should be investigated"和最后一段"We should find it and take it out of production."可知科学家尽力想知道这些气体是来自于哪里,这样才能阻止他们被释放.故选C.
点评 考查学生的细节理解和推理判断能力.做细节理解题时一定要找到文章中的原句,和题干进行比较,再做出正确选择.在做推理判断题时不要以个人的主观想象代替文章的事实,要根据文章事实进行合乎逻辑的推理判断.
A. | checking | B. | weighing | C. | balancing | D. | examining |