第一节完形填空（共10小题；每小题2分，满分20分）
阅读下面短文，掌握其大意，然后从21-3各题所给的A、B、C和D项中，选出最佳选项，并填写在答题卡上将该选项涂黑。
Everycountr yhasitsownculture.
Eventhougheachcountr yusesdoors.Doorsmanyhave_21__functionsandpurposeswhichleadto___22__differences.
WhenIfirstcametoAmerica,Inoticedthatapublicbuildinghadtwodifferent__23___andtheyhaddistinctfunctions.Youhavetopushthedoorwiththeword“PUSH”togooutofthebuildingandtopullthedoorwiththeword“PULL”to_24____thebuilding.Thiswasnewtome,becauseweusethe____25__doorinsouthKorea.ForquiteafewtimesIfailedtogooutofashoppingcentr eandwasembarrassed.
Thewayofusingschoolbusdoorswasalso____26__tome.Iusedtotaketheschoolbustoclasses.Theschooldecidedthatwhenthedriveropenedboththefrontandbackdoors,___27_whoweregettingoffthebusshouldgetofffirst,andstudentswhoweregettingonshouldgeton__28_.InsouthKorea,wedonotneedtowaitforpeopletogetoff.Onemorning,Ihurriedtothebus,andwhenthebusdoorsopened,I___29____tr iedtogetontheschoolbusthroughthefrontd oor.Allthestudentsaroundlookedatme,Iwastotally_30__,andmyfacewentr ed.
21_______
A.different
B.important
C.practical
D.unusual
正确答案：C从“leadto22differences”可判断“不同功能导致-------不同”
温馨提示：A不同的B重要的C实践的D不寻常的
