Question

1. Aside from volunteering, how can people help non-profit organizations?

Answer 1

1.a. by donating correct!

2.b. the 1985 earthquake in la Ciudad de Mexico

Answer 2

Aside from volunteering, people can help non-profit organizations by donating.

Poniatowska's work Nadie, nadie, las voces del temblor gives first-person accounts of  the 1985 earthquake in la ciudad de mexico.

So, the answers are:
A. by donating 
And..
B. the 1985 earthquake in la Ciudad de Mexico

Good luck with your studies, I hope this helps~!