－Look, your sister is playing the piano over there.－She ______ be my sister. She has gone to America.

John, look at the time._____ you play the piano at such a late hour?

―Do you know where David is? I couldn’t find him anywhere.―Well. He ______ have gone far — his coat’s still here.

---I stayed at a hotel while in New York.---Oh, did you? You ________ with Barbara.

---Could I have a word with you, mum? ----Oh, dear, if you ______.