People on motor bikes celebrate American President Barack Obama's visit to Kenya by holding up a photo, center top, of the president and First Lady Michelle Obama in Kisumu, Kenya, Saturday, July 25, 2015. President Barack Obama heralded Africa as a continent “on the move” Saturday as he opened a U.S.-sponsored business summit in Kenya, the East African nation where he has deep family ties. (Photo by AP Photo)

A photograph made available on 30 September 2016 showing wind turbines at the site of the highest wind park in Europe at the Griessee, near the Nufenenpass in the Swiss south Alpes, Valais, Switzerland, on 23 September 2016. The four wind turbines of this wind park were developed by the company SwissWinds GmbH and are inaugurated on, 30 September 2016. (Photo by Olivier Maire/EPA)

Yak near Yamdrok lake, Tibet. It is a long-haired bovinae found throughout the Himalayan region of south Central Asia, the Tibetan Plateau and as far north as Mongolia and Russia. The Tibetan economy is dominated by subsistence agriculture. Due to limited arable land, the primary occupation of the Tibetan Plateau is raising livestock, such as sheep, cattle, goats, camels, yaks, dzo, and horses. The Tibetan yak is an integral part of Tibetan life. (Photo by Dennis Jarvis)

American Ballet Theater's dancers are silhouetted as they rehearse for the opening night at the Shanghai Grand Theater in Shanghai, Thursday, November 2, 2023. The American national ballet company is returning to China for the first time in a decade for shows in Shanghai and Beijing in the latest sign strained relations between the United States and China are beginning to thaw. (Photo by Ng Han Guan/AP Photo)

An actress dressed as Wonder Woman walks between visitors during the season inauguration of the Madrid Warner amusement park in San Martin de Valdeiglesias, near Madrid, Spain, March 18, 2016. (Photo by Andrea Comas/Reuters)

This image is NGC 6543 known as the Cat's Eye Nebula as it appears to the Chandra X-Ray Observatory and Hubble Telescope. A planetary nebula is a phase of stellar evolution that the sun should experience several billion years from now, when it expands to become a red giant and then sheds most of its outer layers, leaving behind a hot core that contracts to form a dense white dwarf star. This image was released October 10, 2012. (Photo by J. Kastner/NASA/CXC/RIT)

Indonesian tourists take photos at the Marina Bay in Singapore May 14, 2015. When Singapore celebrated its 50th birthday as an independent country in August,the city state bore little resemblance to the tiny island nation that was expelled from Malaysia in 1965. Its physical stature has swollen by 20 percent thanks to one of the world's most aggressive land reclamation drives. (Photo by Edgar Su/Reuters)

Pausing for a selfie as plum blossoms burst into bloom in Dujiangyan City, in southwest China’s Sichuan province on February 20, 2024. (Photo by Splash News and Pictures)