Men selling sheep wait for customers at a local livestock market, ahead of the Eid al-Adha festival, in Lagos, Nigeria September 11, 2016. (Photo by Akintunde Akinleye/Reuters)

A small section of the expanding remains of the Veil Nebula, a massive star that exploded about 8,000 years ago. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. Image taken by NASA's Hubble Space Telescope. Released September 24, 2015. (Photo by Reuters/NASA/ESA/Hubble Heritage Team)

In this November 21, 2015 photo, Camila Lopez Rivas, 14, poses for portraits on a beach in Havana, Cuba, as an assistant lifts the train of her dress to make it look like its flying in the wind. Camila lives in Miami, the daughter of a truck driver who left Cuba when she was a baby. She doesn't remember the island, but wanted to return for the photographs and videos that Latin American girls typically take for their 15th birthdays. (Photo by Ramon Espinosa/AP Photo)

In this September 21, 2017, local villagers repair a fishing boat in Shah Porir Dwip, an island by the Bay of Bengal at Bangladesh’s southern tip. This island can mean both hope and death for the Rohingya Muslims who are desperate to escape the violence that has engulfed their lives in Myanmar’s Rakhine state. High tide or low, day or night, rough waters or calm, when they can find a boat, the Rohingya take their chance to flee to Bangladesh. More than 430,000 have left Myanmar in less than a month. (Photo by Bernat Armangue/AP Photo)

Common squirrel monkeys observe their Christmas present, a box full of mealworms, at the South America enclosure of the Budapest Zoo, in Budapest, Hungary, 24 December 2017. (Photo by Photo by Attila Kovacs/EPA/EFE/Rex Features/Shutterstock)

Teenage girls are all steamed up these days about straight hair. The steam iron is replacing the huge rollers on which countless teens slept every night to achieve the height and curls fashionable until. The same girls endure having their hair stretched to absolute straightness on the ironing board, and then ironed to keep it that way. Unlike the roller setting, this takes teamwork. Gay Stilley, 14, goes through an ironing session with a couple of her friends at the Stilley Home in Glen Oaks, Queens, New York City on December 23, 1964. With a wary eye, Gay tries to watch the straightening process as one friend stretches her hair with a comb and another does the ironing, in the Stilley kitchen. (Photo by Marty Zimmerman/AP Photo)

In this Wednesday, January 3, 2018 photo, yoga instructor Danuta Wolk-Laniewski, demonstrates goat yoga at the Aussakita Acres farm in Manchester, Conn. The farm is partnering with the Hartford Yard Goats, the Double-A affiliate of the Colorado Rockies baseball team, to offer goat yoga at Dunkin Donuts Park, the team's $71 million stadium in Hartford. (Photo by Pat Eaton-Robb/AP Photo)

A German special anti-tank gun is ready to fire during the army maneuvers in Silesia, Poland, on September 22, 1928. (Photo by AP Photo)