Ultra- trailers compete at sunrise on September 2, 2017 in Courmayeur, Italy, during the 15 th edition of the Mount Blanc Ultra Trail (UTMB), a 170 km race around the Mont Blanc crossing France, Italy and Switzerland. The 15 th Ultra- Trail du Mont- Blanc (UTMB) is a mountain ultramarathon with numerous passages in high altitude (>2500 m) and in difficult weather conditions (night, wind, cold, rain or snow). (Photo by Jeff Pachoud/AFP Photo)

Iraqi army soldiers attempt to move their truck stuck in the mud near the village of Al-Boutha al-Sharqiyah, west of Mosul, on December 2, 2016, during a broad offencive by Iraq forces to retake the main hub city from Islamic State group jihadists. (Photo by Ahmad Al-Rubaye/AFP Photo)

A female forest guard carries a tranquillizer gun in the Gir National Park and Wildlife Sanctuary in Sasan, in Gujarat December 2, 2014. The sanctuary, which is home to Asiatic lions in India, has an area of 1,412 sq km in which female guards were employed for the first time in India in 2007. The guards fetch a monthly salary of around $148 for working almost 12 hours a day, six days a week, said one of the female guards. (Photo by Anindito Mukherjee/Reuters)

A women wearing a mask to protect from extreme smog visits the Tiananmen Gate in Beijing December 8, 2015 as China's capital issues its first ever "red alert" for pollution. (Photo by Damir Sagolj/Reuters)

Actor Jackie Chan poses with student performers after participating in a leg of the Beijing 2022 Winter Olympics Torch Relay at the Badaling Great Wall on February 3, 2022 outside Beijing, China. (Photo by Kevin Frayer/Getty Images)

This picture taken on August 4, 2016 shows three orphaned orangutan babies hanging in a tree whilst attending “jungle school” at the International Animal Rescue centre outside the city of Ketapang in West Kalimantan. (Photo by Bay Ismoyo/AFP Photo)

Dakar Rally, 2017 Paraguay-Bolivia-Argentina Dakar rally, 39th Dakar Edition, First stage from Asuncion, Paraguay to Resistencia, Argentina on January 2, 2017. Adrien Metge of France pushes his Sherco. (Photo by Ricardo Moraes/Reuters)