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时间:2019-10-30
《备战高考英语一轮复习第八套英语4Units1_2单元训练(B卷,含解析)》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、此卷只装订不密封班级姓名准考证号考场号座位号单元训练金卷·高三·英语卷(B)英语4Units1-2注意事项:1.答题前,先将自己的姓名、准考证号填写在试题卷和答题卡上,并将准考证号条形码粘贴在答题卡上的指定位置。2.选择题的作答:每小题选出答案后,用2B铅笔把答题卡上对应题目的答案标号涂黑,写在试题卷、草稿纸和答题卡上的非答题区域均无效。3.非选择题的作答:用签字笔直接答在答题卡上对应的答题区域内。写在试题卷、草稿纸和答题卡上的非答题区域均无效。4.考试结束后,请将本试题卷和答题卡一并上交。第Ⅰ卷第一部分听力(共两节,满
2、分30分)略第二部分阅读理解(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的四个选项(A、B、C和D)中选出最佳选项。AAfreshlybakedrollisasdelightfulasasoft,lightcloudonasummer’sday.Whatgivesbreadmuchofitsappealingtextureisgluten(麸质),agroupofproteinsfoundinwheat.Butinpeoplewithceliacdisease(乳糜泻),gl
3、utendamagesthesmallintestine(肠).Manyothersmayhavemilderglutenintoleranceandavoidfoodsthatcontainit.Mostgluten-freebreadismadefromalternativeflourssuchasriceorpotato,soittastesandfeelsdifferentfromwheatbread.Now,however,researcherssaythattheyhavefoundawaytogenetic
4、allyengineerwheatthatcontainsfarlessofthemosttroublesometypeofgluten—butstillhasotherproteinsthatgivebreaditscharacteristictasteandspringiness.Geneticallymodifiedcropsarethesubjectoffiercedebatearoundtheworld.ThebiggestconcerninvolvesthepracticeofinsertingDNAfrom
5、onespeciesintoanother,saysFranciscoBarro,aplantbiotechnologist.Toavoidthisgeneticcrossover,Barroandhiscolleaguesusedthegene-editingtechniqueCRISPR/Cas9tocutselectedgenesfromawheatgenome(基因组).Theirstudyzeroedinonalpha-gliadins(α-胶质蛋白),glutenproteinsbelievedtobewhe
6、at’smajortroublemakersintheimmunesystem.Theresearchersdesignedbitsofgeneticmaterialthatdirectedthescissor-likeCas9proteintocutout35ofthe45alpha-gliadingenes.WhenthemodifiedwheatwastestedinaPetridish,itproducedan85percentweakerimmuneresponse,theteamreportedonlinel
7、astSeptemberinPlantBiotechnologyJournal.WendyHarwood,acropgeneticistattheJohnInnesCenterinEngland,whowasnotpartofthestudy,notesthattheengineeredwheathasalongwaytogobeforeitcanbeturnedintoanythingmarketable.“Idon’tthinkit’stheendofthestory.”shesays.“Thisisjustarea
8、llyimportantstepinmaybeproducingsomethingthatisgoingtobeincrediblyuseful.”Todevelopacompletelysafestrainofwheatforceliacpatients,theresearchersmayneedtotargetm
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