Holly Elson, Visitor Programmes Manager at Royal Botanic Gardens, poses for a photograph in the hedgerow 'plantscape' exhibit of the Secret World of Plants festival, at the Kew Gardens in London, Britain, May 6, 2021. REUTERS/John Sibley

Members of The King's Troop Royal Horse Artillery fire a gun salute to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Members of The King's Troop Royal Horse Artillery prepare to fire a gun salute to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Members of The King's Troop Royal Horse Artillery prepare to fire a gun salute to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Members of The King's Troop Royal Horse Artillery prepare to fire a gun salute to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

A member of The King's Troop Royal Horse Artillery places empty shells into boxes in advance of a gun salute to commemorate the death of Britain's Prince Philip, Duke of Edinburgh, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Holly Archer, 34, is monitored after receiving her coronavirus disease (COVID-19) vaccine as vaccine eligibility expands to anyone over the age of 16 at the Bradfield Community Center through Health Partners of Western Ohio in Lima, Ohio, U.S., March 29, 2021. REUTERS/Megan Jelinger

Holly Archer, 34, is monitored after receiving her coronavirus disease (COVID-19) vaccine as vaccine eligibility expands to anyone over the age of 16 at the Bradfield Community Center through Health Partners of Western Ohio in Lima, Ohio, U.S., March 29, 2021. REUTERS/Megan Jelinger

Britain's Chief Medical Officer for England Chris Whitty gives an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

The view from behind the lectern at the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

The view from behind the lectern at the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

The view from behind the lectern at the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty gives an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

General view of the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

General view of the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

General view of the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Scientific Adviser Patrick Vallance gestures as he gives an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

General view of the new Downing Street Briefing Room ahead of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

General view of the new Downing Street Briefing Room ahead of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Athletics - 2021 European Indoor Athletics Championships - Arena Torun, Torun, Poland - March 5, 2021 Britain's Holly Mills REUTERS/Aleksandra Szmigiel

Visitors watch as sap from maple trees is boiled down into maple syrup in the evaporator in the sugar house at Hollis Hills Farm in Fitchburg, Massachusetts, U.S., March 13, 2021. REUTERS/Brian Snyder

Maple syrup is poured out of the evaporator in the sugar house at Hollis Hills Farm in Fitchburg, Massachusetts, U.S., March 13, 2021. REUTERS/Brian Snyder

Maple syrup is poured out of the evaporator in the sugar house at Hollis Hills Farm in Fitchburg, Massachusetts, U.S., March 13, 2021. REUTERS/Brian Snyder

Sap from a maple tree drips into a bucket to be boiled down into maple syrup at Hollis Hills Farm in Fitchburg, Massachusetts, U.S., March 13, 2021. REUTERS/Brian Snyder

Visitors watch as sap from maple trees is boiled down into maple syrup in the evaporator in the sugar house at Hollis Hills Farm in Fitchburg, Massachusetts, U.S., March 13, 2021. REUTERS/Brian Snyder

Athletics - 2021 European Indoor Athletics Championships - Arena Torun, Torun, Poland - March 7, 2021 Britain's Holly Archer celebrates on the podium with her silver medal after finishing second in the women's 1500m final REUTERS/Aleksandra Szmigiel

Athletics - 2021 European Indoor Athletics Championships - Arena Torun, Torun, Poland - March 7, 2021 Britain's Holly Archer celebrates on the podium with her silver medal after finishing second in the women's 1500m final REUTERS/Aleksandra Szmigiel

Athletics - 2021 European Indoor Athletics Championships - Arena Torun, Torun, Poland - March 7, 2021 Britain's Holly Archer celebrates on the podium with her silver medal after finishing second in the women's 1500m final REUTERS/Aleksandra Szmigiel

Athletics - 2021 European Indoor Athletics Championships - Arena Torun, Torun, Poland - March 7, 2021 Britain's Holly Bradshaw and Belarus' Iryna Zhuk celebrate on the podium with their bronze medals after finishing joint third in the pole vault women's REUTERS/Aleksandra Szmigiel

Athletics - 2021 European Indoor Athletics Championships - Arena Torun, Torun, Poland - March 7, 2021 Switzerland's Angelica Moser celebrates on the podium with her gold medal after winning the pole vault women's with second placed Slovenia's Tina Sutej and third placed Britain's Holly Bradshaw and Belarus' Iryna Zhuk REUTERS/Aleksandra Szmigiel

Athletics - 2021 European Indoor Athletics Championships - Arena Torun, Torun, Poland - March 6, 2021 Belgium's Elise Vanderelst celebrates after winning the Women's 1500m final with second placed Britain's Holly Archer and third placed Germany's Hanna Klein REUTERS/Aleksandra Szmigiel

Athletics - 2021 European Indoor Athletics Championships - Arena Torun, Torun, Poland - March 6, 2021 Britain's Holly Bradshaw in action during the Women's Pole Vault final REUTERS/Aleksandra Szmigiel

Athletics - 2021 European Indoor Athletics Championships - Arena Torun, Torun, Poland - March 5, 2021 Britain's Holly Mills in action during the women's pentathlon 800m REUTERS/Lukasz Szelag