Whenyoucutyourskin,youbleed(流血).Ifapersonlosesalotofblood,hewillbecomeillandmaydie.Bloodisveryimportant.Peoplehavealwaysknownthat.Atonetime,somepeopleevendrankbloodtomakethemstrong!
Whendoctorsunderstandhowbloodgoesaroundinsidethebody,theytrywaysofgivingbloodtopeoplewhoneedit.Theytakebloodfromthehealthypeopleandgiveittosickpeople.Thiscalled“bloodtransfusion”.Thebloodgoesfromthearmofthehealthypersonintothearmofthesickperson.
Buttherearetwoproblems.First,itdoesnotalwayswork.Sometimespeoplediewhentheyhavebloodtransfusion.Later,doctorsfindthatwedonotallhavethesamekindofblood.Therearefourgroups—O,A,BandAB.Weallhavebloodofoneofthesegroups.TheyalsofindthattheycangiveanykindofbloodtogroupAB.ButtheyfindthattheymustgiveA-bloodtoA-bloodpeopleandB-bloodtoB-bloodpeople.IhaveO-groupbloodasmyfatherandthedoctortoldmethatIcouldgivemybloodtoanyoneelsesafely.SoIdid.
Thereisanotherproblem.Togivebloodoftherightkind,doctorshavetofindapersonoftherightbloodgroup.Oftentheycannotfindapersonintime.Iftheyhaveawaytokeeptheblooduntilsomeoneneedsit,theycanalwayshavetherightkindofblood.Atfirst,theyfindtheycankeepitinbottlesforfifteentotwentydays.Theydothisbymakingitverycold.Thentheyfindhowtokeepitlonger.Intheend,theyfindawayofkeepingbloodforaverylongtime.
Wecallaplacewherewekeepmoneya“bank”.Wecallaplacewherewekeepblooda“bloodbank”.Oneday,whenyougrowup,youmaydecidetogivebloodtoa“bloodbank”.Inthiswayyoumaystopsomeonefromdying.Orperhapsonedayyoumaybecomeill.Youmayneedblood.The“bloodbank”willgiveittoyou.
Atonetimepeopleevendrankbloodbecausetheywantedto________.A
becomeill
B
killthemselves
C
makethemselvesstrong
D
cuttheirskin
“Bloodtransfusion”means“________”.A
toknowhowbloodgoesaround
B
togivedoctorshealthyblood
C
totakebloodfromthehealthypeople
D
togivehealthybloodtoasickperson
Doctorsfindthat________.A