—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
My grandfather spends most of his time _______ because he loves nature.
You won’t be______ by the host to the wedding ___ you are a good friend of his.
You forgot to go to the meeting? You _____ important things. It’s so_______.
It was _______that they went for a walk in the park.
-- Tom has made great progress. -- _______, and _______.