Unit3Underthesea课时作业Ⅰ.阅读理解(2019·北京高考)Bytheendofthecentury,ifnotsooner,theworld'soceanswillbebluerandgreenerthankstoawarmingclimate,accordingtoanewstudy.Attheheartofthephenomenonlietinymarinemicroorganisms(海洋微生物)calledphytoplankton.Becauseofthewaylightreflectsofftheorganisms,thesephytoplanktoncreatecolourfulpatternsattheoceansurface.Oceancolourvariesfromgreentoblue,dependingonthetypeandconcentrationofphytoplankton.Climatechangewillfuelthegrowthofphytoplanktoninsomeareas,whilereducingitinotherspots,leadingtochangesintheocean'sappearance.Phytoplanktonliveattheoceansurface,wheretheypullcarbondioxide(二氧化碳)intotheoceanwhilegivingoffoxygen.Whentheseorganismsdie,theyburycarboninthedeepocean,animportantprocessthathelpstoregulatetheglobalclimate.Butphytoplanktonarevulnerabletotheocean'swarmingtrend.Warmingchangeskeycharacteristicsoftheoceanandcanaffectphytoplanktongrowth,sincetheyneednotonlysunlightandcarbondioxidetogrow,butalsonutrients.StephanieDutkiewicz,ascientistinMIT'sCenterforGlobalChangeScience,builtaclimatemodelthatprojectschangestotheoceansthroughoutthecentury.Inaworldthatwarmsupby3℃，itfoundthatmultiplechangestothecolouroftheoceanswouldoccur.Themodelprojectsthatcurrentlyblueareaswithlittlephytoplanktoncouldbecomeevenbluer.Butinsomewaters,suchasthoseoftheArctic,awarmingwillmakeconditionsriperforphytoplankton,andtheseareaswillturngreener.“Notonlyarethequantitiesofphytoplanktonintheoceanchanging，”shesaid,“butthetypeofphytoplanktonischanging.”Andwhydoesthatmatter?Phytoplanktonarethebaseofthefoodweb.Ifcertainkindsbegintodisappearfromtheocean,Dutkiewiczsaid,“itwillchangethetypeoffishthatwillbeabletosurvive.”Thosekindsofchangescouldaffectthefoodchain.Whatevercolourchangestheoceanexperiencesinthecomingdecadeswillprobablybetoogradualandunnoticeable,buttheycouldmeansignificantchanges.“It'llbeawhilebeforewecanstatisticallyshowthatthechangesarehappeningbecauseofclimatechange，”Dutkiewiczsaid,“butthechangeinthecolouroftheoceanwillbeoneoftheearlywarningsignalsthatwereallyhavechangedourplanet.”篇章导读：本文是一篇说明文。调查表明，由于气候变暖，全球的海洋将会变得更蓝、更绿。1．Whatarethefirsttwoparagraphsmainlyabout?A．Thevariouspatternsattheoceansurface.B．Thecauseofthechangesinoceancolour.C．Thewaylightreflectsoffmarineorganisms.D．Theeffortstofuelthegrowthofphytoplankton.答案：B段落大意题。文章第一段点题：由于气候变暖，全球的海洋将会变得更蓝、更绿。第二段介绍由于光从生物体反射的方式，这些浮游植物在海洋表面形成了五颜六色的图案；气候变化又使得这些浮游植物在某些区域加速生长而在其他地方有所减少，导致海洋表面的颜色变化。由此可知前两段讲了海洋颜色变化的原因，故B项正确。2．Whatdoestheunderlinedword“vulnerable”inParagraph3probablymean?A．Sensitive.B．Beneficial.C．Significant.D．Unnoticeable.答案：A词义猜测题。画线词后一句提到，气候变暖改变了海洋的主要特点并能影响浮游植物的生长，因为它们要生长不仅仅需要阳光和二氧化碳，也需要营养。由此可知，这些浮游植物对海洋变暖很敏感，故A项正确。3．Whatcanwelearnfromthepassage?A．Phytoplanktonplayadecliningroleinthemarineecosystem.B．Dutkiewicz'smodelaimstoprojectphytoplanktonchanges.C．Phytoplanktonhavebeenusedtocontrolglobalclimate.D．Oceanswithmorephytoplanktonmayappeargreener.答案：D推理判断题。文章倒数第二段提到这些浮游植物是海洋食物链的基础，如果某些种类的浮游植物消失了，会影响能存活的鱼的类型，从而影响海洋食物...
