-----Someone is knocking at the door.It ____ be Tom .

-----Someone is knocking at the door.It ____ be Tom . Someone is knocking at the door.Who it be?— It be Tom.He is Someone is knocking at the door._must be Tom Someone is knocking at the door.____ is it? someone is knocking at the door.___must be Tom.为什么用he而不用it? Someone is knocking at the door.It be Tom because he Shangha 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 Venis?—No,it ___ b Someone is knocking at the door,but who can____ be? --Listen! Someone is knocking at the door. Who _____it be? ---Listen! Someone is knocking at the door. Who _____it be?