—Whose T—shirt is this? Is it John's?—It ______ be his. It's too small for him.
He is a writer _____ a singer.
She was heard _____ an English song in her home last night.
Not only his parents but also his brother _____ to the Summer Palace. They haven’t been back.
Tell me everything _____ you know.
I have many hobbies, _______collecting stamps, playing football and so on.