No, don't really stop me.
This is about a very addictive quiz website that someone recently pointed out to me called Freerice.com
You register and then you choose a category and answer the multiple choice questions. For every question that you get right, Freerice.com donate 10 grains of rice to hungry people around the world. I have checked it out and it is a genuine website. Snopes agrees.
The whole thing is paid for by the advertisers using the site.
The questions get progressively harder. The English Vocabulary is fun, but I enjoyed the Flags of the World and the Chemical Symbols as well.
You can try it without registering. Give it a go.