Trains to Oxford..every hour in the morning 1 left leaves 3is leave 4leave 2.This problem..very often 1.isn't happen

1. Trains to Oxford leave every hour in the morning.2. This problem doesn\'t happen very often.3.That ring is very expensive. 4. Where is your car?- It\'s at home. It isn\'t working at the moment. 5. I left the party when it started to rain.6. When I was cooking the dinner, I heard a strange noise. 7. The two men were stopped by the police yesterday. 8. She offered to do the washing-up. 9. I will buy that camera if it doesn\'t cost too much.