—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
We'd better get up earlier than usual if we want to catch the train, ____?
I once heard him ____ that a rainbow (彩虹) was a bridge from earth to heaven.
____, the amount left in the bank is hardly worth mentioning.
If the man is only interested in your looks, _____ just shows how shallow he is.
Which person do you refer to, the one with ______ long hair or the one with _______ long beard?