Unless

https://www.ecenglish.com/learnenglish/lessons/unless-and-if

Charities and NGOs

https://topnonprofits.com/lists/types-of-charities/

Why and how of effective altruism

https://www.ted.com/talks/peter_singer_the_why_and_how_of_effective_altruism

Conditionals:

http://www.englisch-hilfen.de/en/exercises_list/if.htm

Despite/ although:

https://learnenglish.britishcouncil.org/en/grammar-reference/spite-despite-although

http://www.perfect-english-grammar.com/linking-words-contrast.html