Truefaith,
I think you need to take on board what people here are saying. Learning the answers is not the way to understand aircraft systems.
When you take an exam with multi choice answers the idea is to test your knowledge of a sample of all things related to the subject. Your knowledge should be much wider than just the questions asked.
Your knowledge of engines seems to be at a fairly basic level.
e.g. Water injection is used to cool the combustion chamber, not as you thought , only at high temp or altitude. It is (was) often used in high temp conditions but not exclusively so.
For turbine engines I would suggest you get a copy of "The Jet Engine" published by Rolls Royce and "read and inwardly digest" (as my teachers used to say) so you have a better understanding of the subject, and then try to answer the questions yourself. Then if you are having trouble, people here will be only too pleased to help you.
Best regards, Dixi.