An employee of the National Park Service takes a selfie with President Barack Obama, left, in the background meeting with the crowd after a tour of Everglades National Park on Earth Day, Wednesday, April 22, 2015, in Florida. Obama used the visit to warn of the damage that climate change is already inflicting on the nation's environmental treasures. (Photo by Lynne Sladky/AP Photo)

An Alitalia plane approaches to land as starlings fly at Fiumicino international airport in Rome October 14, 2013. Italy will have to notify a planned government-led 500-million-euro bailout of near-bankrupt airline Alitalia to EU regulators who will then assess whether the measure complies with EU state aid rules, the European Commission said on Monday. (Photo by Max Rossi /Reuters)

Participants ride horses, hold spears and wear historic armoured suits of the Middle Ages as they compete during the Saint George international knight tournament in Moscow, Russia, May 3, 2015. (Photo by Maxim Zmeyev/Reuters)

Russians play accordions as they walk near the building of the Federal Security Service (FSB, Soviet KGB successor) in Lubyanskaya Square to mark May Day in Moscow, Russia, Sunday, May 1, 2016. As in Soviet times, about one hundred thousand of cheerful workers paraded across Red Square despite a chilly rain, but instead of red flags with the Communist hammer and sickle, they waved the blue flags of the dominant Kremlin party and the Russian tricolor. (Photo by Alexander Zemlianichenko/AP Photo)

Undated handout photo issued by Guinness World Records of Fabio Reggiani from Italy who has made it into the Guinness Book of World Records for constructing the worlds largest rideable motorcycle measuring 5.10 meters (16ft 8.78 in) from the ground to the top of the handlebars. Six times larger than a normal motorcycle, it's 10.03 m long, 2.5 m wide, and weighs approximately 5,000 kg (5 tonnes). (Photo by Guinness World Records/PA Wire)

Sepak Takraw – ISTAF Super Series Korea 2014-15 – Gunsan City, South Korea April 26, 2015: Thailand's Fueangfa (L) in action during the final. (Photo by Jeremy Lee/Reuters)

Robot pianist Teo Tronico performs at the World Robot Conference (WRC) 2017 at Etrong International Exhibition & Convention Center on August 22, 2017 in Beijing, China. The World Robot Conference 2017 is held from August 23 to 27 in Beijing. (Photo by Liu Guanguan/China News Service/VCG via Getty Images)

A string is used to ensure that the skirts of female members of the honour guard are in the same height from the ground as they prepare for a welcoming ceremony for Congo Republic President Denis Sassou Nguesso outside the Great Hall of the People in Beijing, China, July 5, 2016. (Photo by Jason Lee/Reuters)