Complete the sentences in the exercise using 'do', 'does', 'don't', or 'doesn't'.

1) A: Does Helen take the bus? B: Yes, she does. 2) A: Do I need my book? B: No, you don't. 3) A: Does a lion eat leaves? B: No, it doesn't. 4) A: Do you want milk? B: No, I don't. 5) A: Do you live in a big house? B: Yes, we do.