Thomas Stone, a high school junior at Boston Latin School, and Maeve O'Toole and MK Rusnock, high school seniors graduating from Ursuline Academy, wear their prom attire while posing for photographs for Reuters after their prom was cancelled due to the coronavirus disease (COVID-19) outbreak, in the Arnold Arboretum in West Roxbury, Massachusetts, United States May 8, 2020. Picture taken May 8, 2020. REUTERS/Faith Ninivaggi 

Maeve O’Toole, a high school senior graduating from Ursuline Academy, and Thomas Stone, a high school junior at Boston Latin School, walk through the Arnold Arboretum in their prom attire while posing for photographs for Reuters, after their prom was cancelled due to the coronavirus disease (COVID-19) outbreak, in West Roxbury, Massachusetts, U.S. May 8, 2020. Picture taken May 8, 2020. REUTERS/Faith Ninivaggi 

Maeve O'Toole, a high school senior graduating from Ursuline Academy, and Thomas Stone, a high school junior at Boston Latin School, wear their prom attire while posing for photographs for Reuters after their prom was cancelled due to the coronavirus disease (COVID-19) outbreak, at the Arnold Arboretum in West Roxbury, Massachusetts, U.S. May 8, 2020. Picture taken May 8, 2020. REUTERS/Faith Ninivaggi 

Medway High School students Caroline Dickie, Aoife Bergeron, Olivia Dennehey, and Lauren Norton, pose for photographs for Reuters in their prom attire, after their prom was cancelled due to the coronavirus disease (COVID-19) outbreak, in Choate Park in Medway, Massachusetts, U.S. May 17, 2020. Picture taken May 17, 2020. REUTERS/Faith Ninivaggi 

Medway High School students Olivia Dennehey and Aoife Bergeron sit on a park bench in their prom attire while posing for photographs for Reuters after their prom was cancelled due to the coronavirus disease (COVID-19) outbreak, in Choate Park in Medway, Massachusetts, U.S. May 17, 2020. Picture taken May 17, 2020. REUTERS/Faith Ninivaggi 

A member of local hygiene services wears a protective suit and face masks, as he disinfects a Dara, or Koranic school, to stop the spread of the coronavirus disease (COVID-19) in Dakar, Senegal April 1, 2020. REUTERS/Zohra Bensemra 

Empty wardrobes are seen in a kindergarten as schools and kindergartens are closed due to the coronavirus disease (COVID-19) concerns in Cologne, Germany, March 17, 2020. REUTERS/Thilo Schmuelgen 

Rubber boots are seen in a kindergarten as schools and kindergartens are closed due to the coronavirus disease (COVID-19) concerns in Cologne, Germany, March 17, 2020. REUTERS/Thilo Schmuelgen 

A student's lunch box, plate and hair ribbon are pictured in an empty classroom after the government issued an order to close all schools in the country until April 20th as its first coronavirus case was confirmed, in Colombo, Sri Lanka March 13, 2020. REUTERS/Dinuka Liyanawatte 

Workers disinfect a school following new cases of coronavirus in the city, in San Juan, Metro Manila, Philippines, March 9, 2020. REUTERS/Eloisa Lopez 

A graduating student waits to cross the street before Commencement Exercises at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts, U.S., June 7, 2019. REUTERS/Brian Snyder 

A French riot policeman stands next to a burning car as youth and high school students protest against the French government's reform plan, in Nantes, France, December 6, 2018. REUTERS/Stephane Mahe 

French riot police stand near a burning car as youths and high school students protest against the French government's reform plan, in Nantes, France, December 6, 2018. REUTERS/Stephane Mahe 

French riot police stand near a burning car as youths and high school students protest against the French government's reform plan, in Nantes, France, December 6, 2018. REUTERS/Stephane Mahe 

A French riot policeman stands next to a burning car as youth and high school students protest against the French government's reform plan, in Nantes, France, December 6, 2018. REUTERS/Stephane Mahe 

A French riot policeman stands next to a burning car as youth and high school students protest against the French government's reform plan, in Nantes, France, December 6, 2018. REUTERS/Stephane Mahe 

A French riot policeman stands next to a burning car as youth and students protest against the French government's reform plan, in front of the Lycee Gaspard-Monge secondary school in Nantes, France, December 6, 2018. REUTERS/Stephane Mahe 

A first-year cadet of a local branch under the Krasnodar University of the Ministry of Internal Affairs takes part in an oath-taking ceremony in Stavropol, Russia October 6, 2018. The sign on the uniform reads "Police". REUTERS/Eduard Korniyenko 

Military school cadets march in front of Paraguay's President Mario Abdo Benitez (not pictured) during a military parade in Asuncion, Paraguay August 15, 2018. REUTERS/Marcos Brindicci 

A man wears a 'mortar board' hat as he relaxes on a deckchair following a graduation ceremony for students at University of Brighton in Brighton, southern Britain, August 3, 2018. REUTERS/Toby Melville 

'Mortar board' hats are thrown in the air following a graduation ceremony for students at University of Brighton in Brighton, southern Britain, August 3, 2018. REUTERS/Toby Melville 

'Mortar board' hats are thrown in the air following a graduation ceremony for students at University of Brighton in Brighton, southern Britain, August 3, 2018. REUTERS/Toby Melville 

Kindergarten pupils wave national flags as Chinese Premier Li Keqiang reviews the guard of honour with Japan's Prime Minister Shinzo Abe during a welcoming ceremony before their bilateral talks at Akasaka Palace state guest house in Tokyo, Japan May 9, 2018. REUTERS/Toru Hanai TPX IMAGES OF THE DAY 

A Buddhist prays in front of the site of Beichuan Middle School which was buried by boulders in the 2008 Sichuan earthquake, ahead of Qingming Festival or Tomb Sweeping Day in the city of Beichuan, Sichuan province, China, April 4, 2018. REUTERS/Jason Lee SEARCH "BEICHUAN ANNIVERSARY" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A person holds a sign on the side of a class walk out by the Richard R. Green High School of Teaching during a National School Walkout in Manhattan, New York City, U.S., March 14, 2018. REUTERS/Andrew Kelly 

Yazidi students are seen at school in the Sharya camp, in Duhok, Iraq February 23, 2018. Picture taken February 23, 2018. REUTERS/Ari Jalal 

Residents take part in a vigil led by the Junior Newtown Action Alliance to mourn students and teachers lost in a mass shooting in Florida's Stoneman Douglas High School in Newtown, CT, U.S. February 23, 2018. REUTERS/Michelle McLoughlin 

Slippers are pictured at the school compound in Dapchi in the northeastern state of Yobe, where dozens of school girls went missing after an attack on the village by Boko Haram, Nigeria February 23, 2018. REUTERS/Afolabi Sotunde TPX IMAGES OF THE DAY 

A reveller from the Rosas de Ouro Samba School takes part in a carnival celebration at Anhembi Sambadrome in Sao Paulo, February 10, 2018. REUTERS/Paulo Whitaker 

A reveller from the Rosas de Ouro Samba School takes part in a carnival celebration at Anhembi Sambadrome in Sao Paulo, February 10, 2018. REUTERS/Paulo Whitaker 

A Muslim boy learns to read the Koran at a madrassa, or religious school, during the holy month of Ramadan, on the outskirts of Agartala, India May 29, 2017. REUTERS/Jayanta Dey TPX IMAGES OF THE DAY 

Pupils wearing boater hats as part of their school uniform pose for a group picture outside the V & A museum in London, Britain May 9, 2017. REUTERS/Stefan Wermuth 

People stand in voting booths during the second round of the 2017 French presidential election at a polling station inside the Lycee Francais Charles de Gaulle school, in London, Britain May 7, 2017. REUTERS/Hannah McKay 

Somali internally displaced children queue before getting into a classroom at a school beside an IDP camp in Dollow, Somalia April 4, 2017. REUTERS/Zohra Bensemra 

Somali internally displaced children queue before getting into a classroom at a school beside an IDP camp in Dollow, Somalia April 4, 2017. REUTERS/Zohra Bensemra 

A school boy who attends Sri Lankan traditional dance training performs during their graduation ceremony at a Buddhist temple in Colombo, Sri Lanka January 23, 2017. REUTERS/Dinuka Liyanawatte 

A traditional earring is seen on a school boy who attends Sri Lankan traditional dance training before their graduation ceremony at a Buddhist temple in Colombo, Sri Lanka January 23, 2017. REUTERS/Dinuka Liyanawatte 

Canadian Prime Minister Justin Trudeau (L) and Quebec Premier Philippe Couillard (C) have a selfie taken with a student as they visit the site of the Universite de Montreal's new Science Complex in Montreal, December 16, 2016. REUTERS/Christinne Muschi 

Canadian Prime Minister Justin Trudeau (C), Quebec Premier Philippe Couillard (2ndR) and Montreal mayor Denis Coderre (4th L) pose for photos with future students as they visit the site of the Universite de Montreal's new Science Complex in Montreal, December 16, 2016. REUTERS/Christinne Muschi 

Bryan Waite, a US navy officer based in JSA area for U.N. command, high-fives children at the Daesungdong Elementary School, a school inside the demilitarised zone separating the two Koreas, in Paju, South Korea, November 22, 2016. REUTERS/Kim Hong-Ji SEARCH "DMZ" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Santa Jerry Julian of Colorado Springs, Colorado hides in the grass following a ride on the Polar Express during a field trip from the Charles W. Howard Santa Claus School in Midland, Michigan, U.S. October 28, 2016. REUTERS/Christinne Muschi SEARCH "BECOMING SANTA" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES TPX IMAGES OF THE DAY

School girls throw poppies into a fountain during an Armistice Day event at Trafalgar Square in London, Britain November 11, 2016. REUTERS/Toby Melville TPX IMAGES OF THE DAY

A hooded youth throws a petrol bomb at riot police standing guard at the parliament premises, during a demonstration of school students against education reforms, in Athens, Greece, November 7, 2016. REUTERS/Alkis Konstantinidis

Students of the General Yermolov Cadet School and members of a Cossack community undergo military training at a boot camp set up by the Russkiye Vityazi (Russian Knights) military patriotic club in the village of Sengileyevskoye in Stavropol region, Russia, November 1, 2016. Picture taken November 1, 2016. REUTERS/Eduard Korniyenko 

Students of the General Yermolov Cadet School and members of a Cossack community undergo military training at a boot camp set up by the Russkiye Vityazi (Russian Knights) military patriotic club in the village of Sengileyevskoye in Stavropol region, Russia, November 2, 2016. REUTERS/Eduard Korniyenko 

Children get their meals during military training undergone by students of the General Yermolov Cadet School and members of a Cossack community at a boot camp of the Russkiye Vityazi (Russian Knights) military patriotic club in the village of Sengileyevskoye in Stavropol region, Russia, November 1, 2016. Picture taken November 1, 2016. REUTERS/Eduard Korniyenko 

A girl stands near a model showing the organization of a gas mask during military training undergone by students of the General Yermolov Cadet School and members of a Cossack community at a boot camp of the Russkiye Vityazi (Russian Knights) military patriotic club in the village of Sengileyevskoye in Stavropol region, Russia, November 1, 2016. Picture taken November 1, 2016. REUTERS/Eduard Korniyenko 

A police officer shows the functions of a gun to schoolgirls during their visit inside a police station as part of the 50th Raising Day celebrations of Chandigarh Police in Chandigarh, India, November 2, 2016. REUTERS/Ajay Verma TPX IMAGES OF THE DAY 

A migrant is seen near the jungle school as he waits for his transfer to a reception center during the dismantlement of the camp called the "Jungle" in Calais, France, October 28, 2016. REUTERS/Pascal Rossignol

Iranian and Afghan girls gather at the Emam Hasan Mojtaba school in Kerman, Iran, October 23, 2016. Picture taken on October 23, 2016. REUTERS/Gabriela Baczynska TPX IMAGES OF THE DAY

A masked student at the University of the Western Cape flees as police open fire with rubber bullets and teargas during protests demanding free tertiary education in Cape Town, South Africa, October 19, 2016. REUTERS/Mike Hutchings TPX IMAGES OF THE DAY

A masked student at the University of the Western Cape flees as police open fire with rubber bullets and teargas during protests demanding free tertiary education in Cape Town, South Africa, October 19, 2016. REUTERS/Mike Hutchings 

Women who recently fled the Islamic State's stronghold of Hawija receive food from Barzani Charity Foundation (BCF) at the school at Debaga camp, on the outskirts of Erbil, Iraq October 19, 2016. REUTERS/Zohra Bensemra TPX IMAGES OF THE DAY

Women who recently fled the Islamic State's stronghold of Hawija queue to receive food from Barzani Charity Foundation (BCF) at the school at Debaga camp, on the outskirts of Erbil, Iraq October 19, 2016. REUTERS/Zohra Bensemra 

Women who recently fled the Islamic State's stronghold of Hawija queue to receive food from Barzani Charity Foundation (BCF) at the school at Debaga camp, on the outskirts of Erbil, Iraq October 19, 2016. REUTERS/Zohra Bensemra 

Women who recently fled the Islamic State's stronghold of Hawija queue to receive food from Barzani Charity Foundation (BCF) at the school at Debaga camp, on the outskirts of Erbil, Iraq October 19, 2016. REUTERS/Zohra Bensemra 

Women who recently fled the Islamic State's stronghold of Hawija queue to receive food from Barzani Charity Foundation (BCF) at the school at Debaga camp, on the outskirts of Erbil, Iraq October 19, 2016. REUTERS/Zohra Bensemra 

Women who recently fled the Islamic State's stronghold of Hawija receive food from Barzani Charity Foundation (BCF) at the school at Debaga camp, on the outskirts of Erbil, Iraq October 19, 2016. REUTERS/Zohra Bensemra 

Women who recently fled the Islamic State's stronghold of Hawija receive food from Barzani Charity Foundation (BCF) at the school at Debaga camp, on the outskirts of Erbil, Iraq October 19, 2016. REUTERS/Zohra Bensemra 

Women who recently fled the Islamic State's stronghold of Hawija queue to receive food from Barzani Charity Foundation (BCF) at the school at Debaga camp, on the outskirts of Erbil, Iraq October 19, 2016. REUTERS/Zohra Bensemra