Michael Read, director of Flight Operations from New Zealand-based Martin Aircraft Company, flies a Martin Jetpack during a demonstration at a water park in Shenzhen, China December 6, 2015. KuangChi Science Ltd, a Hong Kong-listed Chinese company and investor of Martin Aircraft, will sell the flying machine in mainland China for 1.6 million yuan ($249,902), according to the company. (Photo by Bobby Yip/Reuters)

Photographer Andy Hall joins the thousands of fans from west Africa who have gathered for Baaba Maal's annual Blues du Fleuve festival in Senegal. Here: Dancers wait to perform on stage. (Photo by Andy Hall/The Observer)

A window cleaner passes a lighter to his colleague while rappelling from a new building in Tianjin March 23, 2007. (Photo by Reuters/Stringer)

U.S. soldiers from the 3rd Cavalry Regiment take part in an artillery exercise on forward operating base Gamberi in the Laghman province of Afghanistan December 24, 2014. (Photo by Lucas Jackson/Reuters)

A man sells traditional doll toys and sweets for children to celebrate the birthday of prophet Muhammad, also known as “mawlid al nabi”, which will fall next week, in a makeshift tent in Cairo, December 30, 2014. (Photo by Mohamed Abd El Ghany/Reuters)

Aymara witchdoctor Ricardo Quispe, also called “Lord of the Lake”, throws coca leaves during a ritual to predict the future, at the witches market of El Alto, on the outskirts of La Paz, December 31, 2014. Dozens of witch doctors tend to a warren of stalls in El Alto, making offerings to give thanks, to promise luck at work or in love, or to call up spirits and banish curses at the end of the year. (Photo by David Mercado/Reuters)

A worker puts the final touches to a replica of a Beijing opera mask made with lemons and oranges during the 82th Lemon festival in Menton February 12, 2015. Over 20,000 hours work for teams to set up the festival and some 145 metric tons of lemons and oranges are used to make displays during the 82th festival, which is themed “Tribulations of a lemon in China”, and runs from February 14 through March 4. (Photo by Eric Gaillard/Reuters)

A woman dressed as a cleaning lady laughs during “Weiberfastnacht” (Women's Carnival) in Cologne February 12, 2015. Women's Carnival marks the start of a week of street festivals, the highlight of the event being “Rosenmontag” (Rose Monday), the final day of the carnival where mass processions are held. (Photo by Ina Fassbender/Reuters)