It ___ be the postman at the door. It’s only six o’clock.

Tom suggested that we __________such a meeting, but Jenny insisted that it _________of great importance.

---Who has made a mess in my room?---Who else       it but your naughty son?

 It was ordered that all the soldiers ____ to the front．

— I heard they went skiing in the mountains last winter. — It ___ true because there was little snow there.