Hard to choose becuase they're all great!
I'd have to agree with Natty though; 2 and 9 (and 10).
2 - because it can represent unity between people, or many people becoming one - each as a link in a chain.
9 - because it gives a good example of the kind of community in which you've been helping as a volunteer. It includes men, women children and even poultry, aha! (nice lighting too).
10 - just because I think there could be a story about the friendship between the two boys (and the volunteer?), that, and it's just a cool pic!
They all give off a sense of warmth and understanding in a small community.