Fireworks explode over a floating Christmas tree in Lagoa Lake in Rio de Janeiro. (Photo by Victor R. Caivano/Associated Press)

Revellers participate in the annual gay pride parade in Amsterdam, Netherlands on August 4, 2018. (Photo by Piroschka van de Wouw/Reuters)

This aerial photo taken on December 28, 2018 shows commercial and residential buildings in Hong Kong. (Photo by Dale De La Rey/AFP Photo)

Pensioner Karl Szmolinsky, who raises a breed of rabbits called giant grays, shows Robert 2, an 8.5kg giant grey who is 74cm long and has ears 25.5cm long, in the backyard of his house on January 15, 2006 in Eberswalde, Germany. In November Szmolinsky sold eight giant greys to a delegation from North Korea, whom he said want to raise the breed as a source of meat for the North Korean population. Szmolinsky said his rabbits reach a maximum weight of 10.5 kg (23.1lbs.). (Photo by Sean Gallup/Getty Images)

Chinese security stands near a Long March 2F rocket carrying Tiangong-1, China's first unmanned space module, stands at the Jiuquan Satellite Launch Center on September 28, 2011 in Jiuquan, Gansu Province of China. Tiangong-1,a small unmanned space lab, will be launched at 21:19 (Beijing time) on September 29, 2011, and will attempt a docking procedure with a Shenzhou 8 spacecraft later in the mission. (Photo by Lintao Zhang/Getty Images)

Marcos Trujillo cleans the engines of a boat made by Contender in preparation for tomorrow's opening day of the four day long Progressive Insurance Miami International Boat Show at the Miami Beach Convention Center on February 15, 2012 in Miami Beach, Florida. The boat show features more than 3,000 boats and 2,000 exhibitors from all over the globe. (Photo by Joe Raedle/Getty Images)

A girl walks past campaign posters for long-time President Yoweri Museveni, as well as for local members of Parliament, on a street in Kampala, Uganda Wednesday, February 17, 2016. On the eve of presidential elections, a heavy police and military presence could be seen in the capital Kampala. (Photo by Ben Curtis/AP Photo)

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)