US President Joe Biden has announced that the US has killed al-Qaeda’s top leader Ayman al-Zawahiri in Afghanistan. Zawahiri was on the US' most-wanted list for about two decades and he had a $25 million bounty on his head. And, the pandemic took a huge toll on schools in India, particularly in rural areas. But a growing number of young people from big cities who are in the tech industry are volunteering in small-town schools. Also, UN Secretary-General Antonio Guterres warned at a nuclear treaty conference in New York that  "luck is not a strategy” and urged treaties to prevent nuclear annihilation. Plus, surfing scientists in Spain are hunting down microplastics.