1.Iwonderhowlongagotheaccident___.
A.takesplaceB.havetakenplaceC.hadtakenplaceD.tookplace
2.Inourcountryboththeoldandtheyoung___.
A.isbeingtakengoodcareB.arebeingtakengoodcareof
C.isbeingtakengoodcareofD.aretakinggoodcareof
3.___hishomework,hehadtostayathomeattheweekend.
A.HavingnotfinishedB.NothavingfinishedC.NothadfinishedD.Hadnotfinished