In this photo posted on Twitter, Sunday, May 3, 2015, and provided by NASA, Italian astronaut Samantha Cristoforetti sips espresso from a cup designed for use in zero-gravity, on the International Space Station. Cristoforetti, the first Italian woman in space, fired up the first espresso machine in space, which uses small capsules, or pods, of espresso coffee. (Photo by AP Photo/NASA)

Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)

Girls practice sit-ups during gymnastics lessons at the Shanghai Yangpu Youth Amateur Athletic School in Shanghai, China, on May 4, 2016. China's sports system has been enormously successful since the country returned to the Olympic fold in 1980, culminating with the host nation topping the medals' table at the 2008 Beijing Olympics. And yet, with the Rio de Janeiro Games less than three months away, the system is beginning to break down due to the shifting demographics of a more prosperous nation. (Photo by Aly Song/Reuters)

A man jumps over a puddle outside Victoria Station, as heavy rain falls, in London, Monday June 20, 2016. Monday marks the Summer Solstice – the longest day of the year and the astronomical change of seasons when days are longest and nights are shortest in the Northern Hemisphere. (Photo by Lauren Hurley/PA Wire via AP Photo)

Festival goers kiss in the “Silent Disco” at the “Music in the Park” stage during the 50th Montreux Jazz Festival, in Montreux, Switzerland, July 9, 2016. (Photo by Anthony Anex/EPA)

The disused bobsled track from the Sarajevo 1984 Winter Olympics is seen on Mount Trebevic, near Sarajevo, September 19, 2013. Abandoned and left to crumble into oblivion, most of the 1984 Winter Olympic venues in Bosnia's capital Sarajevo have been reduced to rubble by neglect as much as the 1990s conflict that tore apart the former Yugoslavia. (Photo by Dado Ruvic/Reuters)

A man walks past a stranded public transport bus on a road flooded by heavy rains in Mumbai, India, August 5, 2016. (Photo by Shailesh Andrade/Reuters)

A fire engine drives away from flames on the ridge, east of Silverwood Lake in Crestline, Calif., Sunday, August 7, 2016. (Photo by Terry Peirson/The Press-Enterprise via AP Photo)