Singer Rihanna performs onstage during the 2011 Billboard Music Awards at the MGM Grand Garden Arena May 22, 2011 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images for ABC)

Four year old Kaleb Stanley (R), from Dublin, reaches up to puncture a giant bubble with the help of his seven year old brother Jacob on London's South Bank on May 9, 2008 in England. (Photo by Peter Macdiarmid/Getty Images)

A Cambodian girl goes through the garbage dump looking for things to recycle in order to survive July 26, 2003 in Phnom Penh, Cambodia. Rampant corruption in this impoverished country has lead to extreme poverty with many Cambodians living below the poverty line. (Photo by Paula Bronstein/Getty Images)

Marie Lou looks out of the window of gypsy folklore wagon on May 24, 2016 in Staintes Maries de la Mere near Arles, France. Gypsies from all over Europe worship “Sara the Black”, their Saint and patroness, for one week. Sara's statue is situated in the crypt of the church. She wears a multicoloured dress and will carried by the gypsies to the sea at this afternoon. (Photo by Thomas Lohnes/Getty Images)

A spider monkey eats a mango at the Paraguana zoo in Punto Fijo, Venezuela July 22, 2016. Some 50 animals have starved to death in the last six months at one of Venezuela's main zoos due to chronic food shortages that have plagued the crisis-stricken South American nation. (Photo by Carlos Jasso/Reuters)

An Afghan woman walks along a street covered with snow on the outskirts of Kabul, Afghanistan February 7, 2017. (Photo by Omar Sobhani/Reuters)

Reuters South Africa-based photographer Juda Ngwenya who documented Nelson Mandela's historic rise to power died on Wednesday. Here: Prostitutes wait at a bar in a plush northern suburb of Johannesburg August 22, 2002. (Photo by Juda Ngwenya/Reuters)

A decorated dish of rice with spinach sauce and egg white is seen at a Hello Kitty-themed Chinese restaurant in Hong Kong, China May 21, 2015. The world's first Chinese-style restaurant dedicated to the Japanese cartoon has been packed out daily despite not officially opening until June 1, 2015. The eatery features some 37 dishes such as dim sum and fried rice, often served in the shape of the girl-cat. (Photo by Bobby Yip/Reuters)