1. I really should... 2. I promise that I'll... 3. I swear I'll / I won't... (a very strong promise) 4. No matter what happens, I'm going to... 5. Come hell or high water, I'll... #4 and #5 express your determination to do something, even if obstacles appear.
Try to give more than a 3 word answer to each question. The examiner wants to hear you talk more than the interviewer. The examiner cannot easily give you a score if you only say yes and no.