Documentation ofpast weather conditions is limited: our main sources of knowledge of conditionsin the distant past are 18____and 19____
18&19. 答案：B ice cores ; C tree rings
原文：For the time before records began, we have only ' proxy records'reconstructed largely from tree rings and ice cores,...
同义替换：Documentation =' proxy records' ; limited =we have only ; main sources = largely from
20. We can deducethat the Little Ice Age was a time of 20____rather than of consistent freezing.
答案：A climatic shifts
原文：The Little Ice Age was far from a deep freeze, however; rather anirregular seesaw of rapid climatic shifts,...
同义替换：consistent freezing = a deep freeze
21. Within it therewere some periods of very cold winters, others of 21____and heavy rain,
原文：The seesaw brought cycles of intensely cold winters and easterly winds,then switched abruptly to years of heavy spring and early summer rains, mildwinters, and frequent Atlantic storms, or to periods of droughts, lightnortheasterly winds, and summer heat waves.
同义替换：very = intensely
22. and yet othersthat saw 22____with no rain at all.
答案：G heat waves
原文：….or to periods of droughts, light northeasterly winds, and summer heatwaves.
同义替换：with no rain at all = droughts
7. In this method, alaser is used to create a line of ionisation by removing electrons from 7____
原文：The idea began some 20 years ago, when high-powered lasers wererevealing their ability to extract electrons out of atoms and create ions.
同义替换：removing…. From = extract …..out of
8. This laser isthen directed at 8____in order to control electrical charges,
答案：C storm clouds
原文：If a laser could generate a line of ionization in the air all the wayup to a storm cloud, this conducting path could be used to guide lightning toEarth
同义替换：is directed at = all the way up to ; controlelectrical charges = guide lightning to Earth
9. This laser isthen directed at 8____in order to control electrical charges, a method which isless dangerous than using 9____
原文：But while rockets are fine for research, they cannot provide theprotection from lightning strikes that everyone is looking for.
同义替换：dangerous = cannot provide the protection
10. As a protection forthe lasers, the beams are aimed firstly at 10____
原文：To stop the laser itself being struck, it would not be pointed straightat the clouds. Instead it would be directed at a mirror, and from there intothe sky.
同义替换：protection = stop….. being struck ; are aimedfirstly at = be directed at , from there into the sky
According to 9____thereis only one correct form of language. Linguists who take this approach tolanguage place great importance on grammatical 10____
9. 答案：H prescriptivists
原文：In its most general sense, prescriptivism is the view that one varietyof language has an inherently higher value than others,…….Adherents to thisvariety are said to speak or write'
correctly';deviations from it are said to be 'incorrect'
同义替换：prescriptivists = Adherents to this variety ;one correct form = deviations from it are said to be 'incorrect'
原文：The authoritarian nature of the approach is best characterized by itsreliance on 'rule' s of grammar.
同义替换：place great importance on = reliance on ;grammatical rules = 'rule' s of grammar
Conversely, the viewof 11____such as Joseph Priestley, is that grammar should be based on 12____
原文：This approach is summarised in the statement that it is the task of thegrammarian to describe, not prescribe….. In the second half of the 18thcentury, we already find advocates of this view, such as Joseph Priestley.
同义替换：descriptivists = describe, not prescribe
12.答案：C popular speech
原文：We already find advocates of this view, such as Joseph Priestley, whoseRudiments of English Grammar (1761) insists that 'the custom of speaking is theoriginal and only just standard of any language’. Linguistic issues, it isargued, cannot be solved by logic and legislation.
同义替换：popular speech = the custom of speaking