Two actors dressed as roboters hold up an illuminated 4 - 0 lettering at the "Leaders Dialogue - Industry 4-0 Made in Germany" during the launch of the "Industry 4-0" platform at the Hannover Messe industrial trade fair in Hanover, central Germany.

Ole Spata/DPA/AFP

Two actors dressed as robots at the launch of the Industry 4-0 platform at the Hannover Messe industrial trade fair in Hanover, Germany

Anti-nuclear activists block one of the entrances to Faslane naval base on the Clyde in Faslane, Scotland. The Scrap Trident campaign is urging voters to back only those candidates who firmly reject the plan to replace the current Trident system

Jeff Mitchell/Getty Images

Anti-nuclear activists block one of the entrances to Faslane naval base on the Clyde in Faslane, Scotland. The Scrap Trident campaign is urging voters to back only those candidates who firmly reject the plan to replace the current Trident system

Fans listen to David Guetta at the Coachella Valley Music and Arts Festival in Indio, California.

Lucy Nicholson/Reuters

Fans listen to David Guetta at the Coachella Valley Music and Arts Festival in Indio, California.

Prime Minister David Cameron poses for a selfie with a local woman as he campaigns in Alnwick, England

Peter Macdiarmid/Getty Images

David Cameron, UK prime minister, poses for a selfie as he campaigns in Alnwick, England ahead of May’s general election.

Nigel Farage, the leader of the United Kingdom Independence Party, laughs during a visit to a factory in Clacton, Essex.

Peter Nicholls/Reuters

Nigel Farage, the leader of the UK Independence party, laughs during a visit to a factory in Clacton, Essex.

The Dome of the Rock is seen in the background as Palestinian youths practice their parkour skills during Friday prayers in Jerusalem's Old City.

Ammar Awad/Reuters

The Dome of the Rock is seen in the background as Palestinian youths practice their parkour skills during Friday prayers in Jerusalem’s Old City.

Serbian Orthodox Christian pilgrims pray as they carry wooden crosses, along the Via Dolorosa (Way of Suffering), during the Orthodox Good Friday procession in Jerusalem's old city.

Thomas Coex/AFP/Getty Images

Serbian Orthodox Christian pilgrims pray as they carry wooden crosses, along the Via Dolorosa (Way of Suffering), during the Orthodox Good Friday procession in Jerusalem’s old city.

Elephants spray tourists with water in celebration of the Songkran water festival in Thailand's Ayutthaya province, north of Bangkok

Chaiwat Subprasom/Reuters

Elephants spray tourists with water in celebration of the Songkran water festival in Ayutthaya province, Thailand

US Secretary of State John Kerry looks at the view of Lake Geneva from his hotel room as the Iran nuclear talks continue, in Lausanne, Switzerland.

Laurent Gillieron/EPA

US Secretary of State John Kerry looks at the view of Lake Geneva from his hotel room as the Iran nuclear talks continue, in Lausanne, Switzerland.

Penitents wait inside San Francisco church to take part in "Nuestro Senor Atado a la Columna, Maria Santisima de la Paz y San Juan Evangelista" Holy Week procession in Arcos de la Frontera, Spain.

Daniel Ochoa de Olza/AP

Penitents wait inside San Francisco church to take part in “Nuestro Senor Atado a la Columna, Maria Santisima de la Paz y San Juan Evangelista” Holy Week procession in Arcos de la Frontera, Spain.

Children watch a 3D war movie at a community theatre in Hefei, Anhui province, China.

William Hong/Reuters

Children watch a 3D war movie at a community theatre in Hefei, Anhui province, China.

A female Syrian soldier from the Republican Guard commando battalion drives a tank during clashes with rebels in the restive Jobar area, in eastern Damascus.

Joseph Eid/AFP/Getty Images

A female Syrian soldier from the Republican Guard commando battalion drives a tank during clashes with rebels in the restive Jobar area, in eastern Damascus.

A photographer takes pictures of South Korean army soldiers taking part in a U.S.-South Korea joint live-fire military exercise at a training field in Pocheon, south of the demilitarized zone.

Kim Hong-Ji/Reuters

A photographer takes pictures of South Korean army soldiers involved in a US/South Korea live-fire military exercise at a training field in Pocheon, south of the demilitarized zone

Mourners line up to enter parliament where founding Singapore Prime Minister Lee Kuan Yew lies in state.

Joseph Nair/AP

Mourners line up to enter parliament where founding Singapore Prime Minister Lee Kuan Yew lies in state

Young Afghan vendors push their ice-cream carts along a road on the outskirts of Mazari-i-Sharif.

Farshad Usyan/AFP/Getty Images

Young Afghan vendors push their ice cream carts along a road on the outskirts of Mazari-i-Sharif.

Lance Corporal Liam Seer-Boylan of the 1st Battalion Grenadier Guards holds an original Waterloo Bugle during the official launch of this summer's Beating Retreat on Horse Guards Parade, London. It will be will be played for the first time in 200 years during the Beating Retreat concert on the 10th and 11th of June.

Rob Stothard/Getty Images

Lance Corporal Liam Seer-Boylan of the 1st Battalion Grenadier Guards holds an original Waterloo Bugle during the official launch of this summer’s Beating Retreat on Horse Guards Parade, London. It will be will be played for the first time in 200 years during the Beating Retreat concert on the 10th and 11th of June. 

Qualified anti-poaching rangers and new recruits train during an "Op-Fok" training session at the Nkwe Tactical Training Academy in Vaalwater in the Limpopo. South Africa.

Stefan Heunis/AFP/Getty Images

Qualified anti-poaching rangers and new recruits train during an “Op-Fok” training session at the Nkwe Tactical Training Academy in Vaalwater in the Limpopo, South Africa.

Ukraine's voluntary militia, called the Azov Battalion, undergoes artillery training.

Marko Djurica/Reuters

Ukraine’s voluntary militia, called the Azov Battalion, undergoes artillery training.

Britain's Queen Elizabeth II  and Prince Philip, Duke of Edinburgh  during the officially named P&O Cruises new flagship Britannia in a glittering ceremony in which a bottle of British Wiston Estate Brut NV was broken against the hull of the 143,000 tons cruise ship in the port of Southampton, Britain,

EPA

Britain’s Queen Elizabeth II and Prince Philip, Duke of Edinburgh, during the official naming of the P&O Cruises new flagship Britannia, in a glittering ceremony in which a bottle of British Wiston Estate Brut NV was broken against the hull of the 143,000 tons cruise ship in the port of Southampton, Britain,

People watch a fight between male small-tail han sheep in Hanhejing village in Huaxian county in central China's Henan province.

  © Wang Zirui/EPA

People watch a fight between male small-tail han sheep in Hanhejing village in Huaxian county in central China’s Henan province