how i go about tackling these sorts of questions is too make sure i'm always directly refering to what is provided in the case study and linking it back to how this impacts sustainable human development and health. Always refer to something that can continue on once the aid organisation has left when talking about sustainability ... eg teaching the local people how to fix and maintain water wells , will empower the individual as well as make it sustainable long after the aid has left because they now have the skills to manage it.
I also tend to feel as though i keep repeating myself throughout the exam, this isn't always a bad thing i don't think ! some of the stuff is the same and i seem to get full marks for the question regardless. I wouldn't be too worried !
i hope this helped a little ! my bad if i rambled on a tad
good luck everyone for the exam tomorrow !