you must ____(knock)on the door before you enter

you must ____(knock)on the door before you enter When you ____ others,you should say sorry at once.A,knock toB,knock atC,kWhen you ____ others,you should say sorry at once.A、knock toB、knock atC、knock onD、knock into Please ____(knock)at the door when you come in. You must knock at the door before you e_____the teachers’office. You must be a teacher,____ ____ knock you down 造句 Tom,____(knock)on the door before you come in next time Before you get into the teachers' office.You must knock( )the door.A.on B.in C.to You must finish it ____(care) First you must ____ ____(穿过）the bridge. 英语完成对话,每空一词A:Will you ____ me plant this tree piease?B:Of course ! What do you _____me to do ?A:Well , I've ____this hole,Hold this stick_____I knock is inB:Ok! Is it _____?A:_____or lessB:What's_____?A:The tree must be _____in th you must be ____(care)when you cross the street. Every number of the band must follow the ____.A．hit B．strike C．beat D．knock (1)It was six.The Greens ____(have) sypper.(2)When you ____(knock) at the door yesterday,I ____(do)some washing. knock knock knock knock