Civil rights leaders, including Dr. Martin Luther King, Jr., sing "We Shall Overcome" at the conclusion of the Selma to Montgomery civil rights march in 1965. Stephen F. Somerstein/Getty Images hide caption

A police officer stands outside the Mossack Fonseca law firm Tuesday as organized crime prosecutors raid the offices in Panama City. Arnulfo Franco/AP hide caption

Smog blankets scyscrapers in Mexico City on March 17. The city is suffering its worst pollution in more than a decade, and cars are required to stay off the street one day a week. Rebecca Blackwell/AP hide caption

Paul Zakayo (left) and Nasa Jackson Mairi were nabbed by a team of park rangers at the Mara Conservancy in Kenya and charged with killing three impalas and a gazelle in the wildlife sanctuary. Greg Warner/NPR hide caption

Ian Burkhart prepares for a training session in Columbus, Ohio. To move muscles in Burkhart's hand, the system relies on electrodes implanted in his brain, a computer interface attached to his skull, and electrical stimulators wrapped around his forearm. Lee Powell/The Washington Post/Getty Images hide caption

Angelica Pereira feeds her daughter Luiza, who was born with microcephaly, at her mother's house in Santa Cruz do Capibaribe, Brazil. Felipe Dana/AP hide caption

Not all financial education classes help us make better financial decisions. But some do. LA Johnson/NPR hide caption

Trump waiting to be introduced during a Donald Trump campaign rally in February in New Hampshire. David Goldman/AP hide caption

Remittances are a worldwide business. Above, an agent in Hong Kong specializes in transferring cash to the Philippines. Nelson Ching/Bloomberg via Getty Images hide caption