2019年高考英语一轮巩固达标练题Unit1GreatScientists含解析新人教版必修5.doc

8GreatScientists李仕才一、阅读理解。Crossingyourlegsisanextremelycommonhabit;mostpeopledon'tevennoticethatthey'redoingitwhentheysitdown.Whileyoumayfinditcomfortabletositwithonekneecrossedovertheotheritmightbecausinghealthproblemsthatyouarenotawareof.AstudypublishedinBloodPressureMonitoringstatedthatsittingwithyourlegscrossedcanincreaseyourbloodpressure.Thereasonforthisisthatthebloodinyourlegshastoworkagainstgravitytobepumpedbacktoyourheartandthatcrossingonelegovertheotherincreasesresistancemakingitevenharderforthebloodtocirculate.Thiscausesyourbodytoincreaseyourbloodpressuretopushthebloodbacktotheheart.Youwon'tfeelanyimmediateeffectsbutrepeateddrawn-outincreasesinbloodpressurecancauselong-termhealthissues.Soplanningtositforalongperiodoftime?Don'tkeepyourlegscrossed.CrossingyourlegsatthekneecanalsocausepressureonthemajornerveinyourlegthatpassesjustbelowyourkneeandalongtheoutsideofyourlegexplainsRichardGravesamedicalexpert.Thispressurecancausenumbnessandtemporaryparalysis(麻痹)ofsomeofthemusclesinyourfootandlegpreventingyoufrombeingabletoraiseyourankle—whatweknowasthat“pinsandneedles”sensation.Whilethefeelingofdiscomfortmayonlylastaminuteortworepeatedlycrossingyourlegsuntiltheyfeelnumbcancausepermanentnervedamage.Sonexttimeyousitdowntrytogetyourselfinthehabitofsittingwithbothofyourfeetonthefloor.Notonlywillithelpyourpostureandstabilitybutitwillalsosaveyourhealthinthelongrun.1.Whatcanwelearnaboutcrossingone'slegs?A.Itisaverybadsocialhabit.B.Itisusuallypracticeddeliberately.C.Itcanmakeothersfeeluncomfortable.D.Itcandoharmtopeople'shealth.2.Accordingtothestudysittingwithyourlegscrossedcan______.A.resistgravityeffectivelyB.affectyourbloodpressure