Please fill the gaps with suitable words:

1. I will try very hard to come and have dinner at your house if I ....... able to.
(a) am (b) was (c) were

2. If you ....... got that job, would you have been able to move to a new house?
(a) have (b) had (c) will have

3. If I ....... very hard, I would have been able to stop smoking.
(a) try (b) would have tried (c) had tried