"Bill Gates, former Microsoft CEO and co-founder of the Bill and Melinda Gates Foundation, speaks as a jar of human feces sits on a podium at the Reinvented Toilet Expo in Beijing, Tuesday, Nov. 6, 2018. With a jar of human feces on a podium next to him, billionaire philanthropist Bill Gates has kicked off a ""Reinvented Toilet"" Expo in China. Gates said Tuesday that the technologies on display at the three-day expo in Beijing represent the most significant advances in sanitation in nearly 200 years. (AP Photo/Mark Schiefelbein)"