A six-year-old acrobat performs on the opening of a tourist festival in Bozhou, Anhui province, China May 3, 2015. (Photo by Reuters/China Daily)

1: Dubai's Burj Khalifa is the tallest building in the world, but perhaps not for long. Saudi Arabia has announced plans to build a 1 kilometer (3,280 foot) tower into the sky, to be named the Jeddah Tower, scheduled for completion in 2020. The Burj Khallifa currently stands at 2,716 ft. (Photo by Matthias Seifert/Reuters)

In this May 1, 2016 photo, a reluctant donkey is alternately pushed and pulled and enticed with carrots toward town hall in order to be dressed for the costume competition at the annual donkey festival in Otumba, Mexico state, Mexico. Otumba was an important donkey market during Spanish colonial times, standing at the crossroads of major roads leading to Mexico City, where the beasts pulled heavy loads and carried travelers. Today, however, farmers use tractors and pickup trucks, and the donkey population is in decline. (Photo by Rebecca Blackwell/AP Photo)

Members of the Apollo Rainbow Dancers stretch out in special A train late on May 4, 1985, in New York. The legendary Apollo Theatre celebrated its 50th anniversary in an official reopening after a 15 month refurbishing with a celebrity studded evening. (Photo by Ray Stubblebine/AP Photo)

Israeli fashion design student from the Shenkar College of Engineering and Design Danit Peleg (R) assists a fashion blogger to wear an outfit from her graduate collection during a conference on 3-D printing in Tel Aviv, Israel September 3, 2015. Peleg, 27, says she spent over 2000 hours to create her graduate collection which is made solely from home 3-D printers. International fashion bloggers, taking part in a project supported by “Stand With Us Israel fellowship”, a non-profit organisation, attended the conference and tried on Peleg's clothing before listening to her talk about her collection. (Photo by Nir Elias/Reuters)

The players of Denmark huddle prior to the FIFA Women's World Cup qualifier match between Denmark and Sweden at Viborg Stadion on September 4, 2018 in Viborg, Denmark. (Photo by Lars Ronbog/FrontZoneSport via Getty Images)

Pilots plan a flight manoeuvre with model aircraft at a military air base in Vasylkiv, Ukraine, August 3, 2016. (Photo by Gleb Garanich/Reuters)

A woman yawns as she sits outside a hospital on a cold winter morning in Srinagar January 3, 2019. (Photo by Danish Ismail/Reuters)