—Who______ it be that is knocking at the door? —
Who______ it be that is knocking at the door?
Someone is knocking at the door.Who it be?— It be Tom.He is
Someone is knocking at the door.___ it be Venis?—No,it ___ b
-Who __it be that is knocking at the door -It__b
someone is knocking at the door.who [ ]it be?
---someone is knocking at the door.Who _____ it be?
-----Someone is knocking at the door.It ____ be Tom .
Is Lucy knocking at the door?No.It _____ be Lucy.She is in J
Is Maria knocking at the door ? ------It( )be her. She is in
Listen! Someone is knocking _________ the door. [  
someone is knocking at the door.It might be the posyman.为什么用
There is someone knocking at the door.It may ________ (be) t