This combination of April 15, 2013 and April 2, 2014 photos show a police officer clearing Boylston Street following a bomb blast near the finish line of the 2013 Boston Marathon, and pedestrians crossing at the same corner nearly a year later in Boston. (Photo by Charles Krupa/AP Photo)

Holly Spring, a New Zealand photographer, says she is inspired by her daughter Violet, who was born with multiple ailments; Hirschsprung’s Disease, a blockage of the large intestine and Symbrachydactyly, a limb abnormality. The series was designed to show her daughter that she “can live a life without obstacles”. (Photo by Holly Spring)

An illustration showing scarecrows pulling a firewood cart beside a road is on display at Kakashi no Sato, or the Scarecrow's Hometown on September 10, 2014 in Himeji, Japan. In this district of Yasutomi in Himeji city, over 100 of scarecrows stand in farmlands and abandoned houses to illustrate the good old Japanese countryside and attract visitors. (Photo by Buddhika Weerasinghe/Getty Images)

Photographer and animal lover Chris Keeney shows how to use a PetCam with your own pet and offers expert technical know-how and inspiring creative suggestions to get you started. This is Coulee, a border collie/golden retriver mix from Lethbridge, Alberta, Canada. (Photo by Chris Keeney/Princeton Architectural Press)

A coil-shaped Helix Nebula showing a fine web of filamentary “bicycle-spoke” features embedded in the colorful red and blue ring of gas. At 650 light-years away, the Helix is one of the nearest planetary nebulae to Earth. A planetary nebula is the glowing gas around a dying, Sun-like star. (Photo by Reuters/NASA)

Ludivine Sagna walks the runway and wears a chocolate costume made by designer and a chocolate maker during the Fashion Chocolate show at Salon du Chocolat at Parc des Expositions Porte de Versailles in Paris, France, October 28, 2014. (Photo by LAURENTVU/SIPA Press)

Miss Hawaii Allison Chu waves to the crowd as she holds one of her shoes during the 2017 Miss America pageant “Show Us Your Shoes” parade Saturday, September 10, 2016, in Atlantic City. (Photo by Chris Szagola/AP Photo)

A humanoid robot named “Yangyang” shows a facial expression during its demonstration at the Global Mobile Internet Conference (GMIC) 2015 in Beijing, China, April 29, 20155. The android was produced jointly by China's Shanghai Yangyang Intellegent Robot Science Service center and Japanese professor Hiroshi Ishiguro, with the aim of popularising robotics among the young. (Photo by Kim Kyung-Hoon/Reuters)