Complete the conversations: 1. I really must to go now! - _____________. A. How long is it? B. Can't you stay? C. What time? 2. Is Mike still doing his homework? - __________________. A. Yes, he does. B. It's ready. C. Let's ask him. 3. I can't understand this letter? - ________________. A. Would you like some help? B. Don't you know? C. I suppose you can. 4. Are you sure the films starts at 10? - ______________. A. Yes, I am. B. No, I didn't. C. Yes, I do.