1.It ________ be the postman at the door.It's only six o'clo

Who's that at the door?____ is the postman.A.She B.This C.It Who is knocking at the door?I think ___ is the postman?A、it ----There's someone at the door.Who____ it be Is it the post --who's that at the door?--____ is a postman. There is someone knocking at the door.It may ________ (be) t is,it's,the,in,at,evening,time,o'clock,begin,begins,six,what It's so cold outside.Could you please keep the door ____(clo 一、There's someboby at the door.____it be Jim?No,it ____be hi Who______ it be that is knocking at the door? 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 .