5、Thefourthfloor.17.Whatcantheyseeonthesecondfloor? A.Technologyintheolddays.B.Inventionsindifferentcenturies. C.Moderninventionsinthe20thcentury.18.Wherecantheyhaveadrink? A.Onthefirstfloor.B.Onthesecondfloor.C.Onthefourthfloor.19.Whichisthemosthelpfulwaytofindmoreinformationaboutthemuseum? A