Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

The Sugar Plum Fairy, Katherine Free, left, dances with the dog, Pig, during the Birmingham's Ballet “Mutt-cracker”, a rendition of the famous ballet “The Nutcracker”, in Birmingham, Alabama, December 8, 2016. (Photo by Brynn Anderson/AP Photo)

People try out the XIM 17 vehicle interior concept unveiled by Yanfeng Automotive Interiors during the North American International Auto Show in Detroit, Michigan, U.S., January 10, 2017. (Photo by Brendan McDermid/Reuters)

Artists perform during the Closing Ceremony of the Rio 2016 Olympic Games at the Maracana Stadium in Rio de Janeiro, Brazil, 21 August 2016. (Photo by Sergei Ilnitsky/EPA)

Hostesses pose for pictures outside the Great Hall of the People before a meeting ahead of Saturday's opening ceremony of the National People's Congress (NPC), in Beijing, China March 4, 2016. (Photo by Jason Lee/Reuters)

A woman carries a water pump to work on February 11, 2017 in Almolonga, Guatemala. The Mayan town in the western highlands district of Quetzaltenango has surged in prosperity in recent years with high-productivity vegetable farming, exporting much of its excess crops to neighborning El Salvador. (Photo by John Moore/Getty Images)

Contestant Nathalie De Oliveira of Brazil prepares backstage before the final show of the Miss International Queen 2016 transgender/transsexual beauty pageant in Pattaya, Thailand, March 10, 2017. Thai contestant Jiratchaya Sirimongkolnawin was crowned Miss International Queen 2016. The 2016 show was postponed from November last year due to Thailand's mourning period of its late King Bhumibol Adulyadej who died at age 88 on October 13, 2016. (Photo by Athit Perawongmetha/Reuters)

Umbrellas are placed over the statute of the Beatles, during a photocall, on Liverpool's waterfront, in Liverpool, England, Wednesday, March 22, 2017. The city of Liverpool is getting set to celebrate the half-centenary of “Sgt. Pepper's Lonely Hearts Club Band”, one of the most influential albums by local heroes The Beatles. (Photo by Peter Byrne/PA Wire via AP Photo)