Runners pass along discarded cups at a refreshment point during the Vienna City Marathon in Vienna, Austria, April 7, 2019.

A view shows a facility, where nearly 100 whales including orcas and beluga whales are held in cages, during a visit of scientists representing explorer and founder of the Ocean Futures Society Jean-Michel Cousteau in a bay near the Sea of Japan port of Nakhodka in Primorsky Region, Russia April 7, 2019. Picture taken April 7, 2019. Press Service of Administration of Primorsky Krai/Alexander Safronov/Handout via REUTERS

Tesla Inc. CEO Elon Musk (C) exits after attending a S.E.C. hearing at the Manhattan Federal Courthouse in New York, April 4, 2019.

Pigeons fly in front of a large poster of Turkish President Tayyip Erdogan in Bursa, Turkey, April 6, 2019.

Traders work on the floor at the New York Stock Exchange (NYSE) in New York, U.S., April 8, 2019.

Israeli Prime Minister Benjamin Netanyahu and his wife Sara wave as Netanyahu speaks following the announcement of exit polls in Israel's parliamentary election at the party headquarters in Tel Aviv, Israel April 10, 2019.

The first ever photo of a black hole, taken using a global network of telescopes, conducted by the Event Horizon Telescope (EHT) project, to gain insight into celestial objects with gravitational fields so strong that no matter or light can escape, is shown in this handout released April 10, 2019. Event Horizon Telescope (EHT)/National Science Foundation/Handout via REUTERS

Rep. Ilhan Omar (D-MN) wipes tears from her eye as she speaks about Trump administration policies towards Muslim immigrants at a news conference by members of the U.S. Congress "to announce legislation to repeal President Trump’s existing executive order blocking travel from majority Muslim countries" outside the U.S. Capitol in Washington, U.S., April 10, 2019.

Soccer Football - Champions League Quarter Final First Leg - Tottenham Hotspur v Manchester City - Tottenham Hotspur Stadium, London, Britain - April 9, 2019 Manchester City's Riyad Mahrez in action

Britain's Prime Minister Theresa May arrives at an extraordinary European Union leaders summit to discuss Brexit, in Brussels, Belgium April 10, 2019. Image used for illustrative purpose.

The 40-metre high Rain Vortex, which is the world's tallest indoor waterfall, is seen from inside Jewel Changi Airport in Singapore, April 11, 2019.

An employee works at Rostvertol aviation plant, owned by Russian Helicopters company, part of Rostec State Corporation, which manufactures commercial and military aircraft including upgraded heavy Mi-26T2V helicopters, during a demonstration tour in Rostov-on-Don, Russia April 4, 2019.

A U.S. Border Patrol agent searches for undocumented migrants after they illegally crossed the Rio Grande near Palmview, Texas, U.S., April 6, 2019.

Identical twins Taiwo Adejare and Kehinde Adejare pose for a picture in Igbo Ora, Oyo State, Nigeria April 4, 2019.

WikiLeaks founder Julian Assange arrives at the Westminster Magistrates Court, after he was arrested in London, Britain April 11, 2019.

Former U. S. President Barack Obama leaves after a meeting with German Chancellor Angela Merkel at the chancellery in Berlin, Germany April 5, 2019.

The Boeoegg, a snowman made of wadding and filled with firecrackers, is burning in a bonfire in the Sechselaeuten square in Zurich, Switzerland April 8, 2019.

Players rest at a baseball stadium in Havana, Cuba April 8, 2019.

U.S. President Donald Trump talks about the U.S.-Mexico border during a fundraising roundtable with campaign donors in San Antonio, Texas, U.S. April 10, 2019.

A military officer is carried by the crowd as demonstrators chant slogans and carry their national flags, after Sudan's Defense Minister Awad Mohamed Ahmed Ibn Auf said that President Omar al-Bashir had been detained "in a safe place" and that a military council would run the country for a two-year transitional period, outside Defence Ministry in Khartoum, Sudan April 11, 2019.

A "Baby Trump" balloon floating during a protest against U.S. President Donald Trump visit to Calexico, California, as seen from Mexicali, Mexico April 5, 2019.

Kids row on a styrofoam block through a flooded street during heavy rains in the Guaratiba neighborhood in Rio de Janeiro, Brazil April 10, 2019. Image for illustrative purposes.