I will be happy if I pass my exam (be; pass). If you leave now, you will catch the train (leave; catch). John says he will work as a taxi-driver if he needs money (work; need). If I am not free tomorrow evening, I will see you on Friday (not be; see). Marry will study Chinese next year if she has time (study; have). I will drive you to the station if I can find my car keys (drive; can). If he marries her, he will not have a happy life (marry; not have). Will you stop smoking if the doctor tells you that you must? (stop; tell). If we talk to the boss very politely, will he listen to us? (talk; listen).