Weapons and helmets are seen atop the backpacks of U.S. Military Academy (USMA) cadets during tactical and physical training activities as part of Cadet Summer Training at West Point, New York, U.S., August 7, 2020. REUTERS/Mike Segar

A man holding a backpack with an image of the eyes of late president Hugo Chavez walks off the punishment area set by security forces for people who disrespect social distancing measures, in the low income neighbourhood of Petare, amid the outbreak of the coronavirus disease (COVID-19), in Caracas, Venezuela August 5, 2020. Picture taken August 5, 2020. REUTERS/Manaure Quintero

Dyson design engineer Jessica Rowley examines pollution data gathered by a special backpack designed to monitor air quality during the COVID-19 lockdown on Clapham Common, London, Britain June 29, 2020. Picture taken June 29, 2020. REUTERS/Stuart McDill

A badge on a backpack designed to monitor pollution during the COVID-19 lockdown reads "I'm an Air Quality Scientist" as Dyson design engineer Jessica Rowley examines data on her laptop on Clapham Common, London, Britain June 29, 2020. Picture taken June 29, 2020. REUTERS/Stuart McDill

A badge on a backpack designed to monitor pollution during the COVID-19 lockdown reads "I'm an Air Quality Scientist" as Dyson design engineer Jessica Rowley examines data on her laptop on Clapham Common, London, Britain June 29, 2020. Picture taken June 29, 2020. REUTERS/Stuart McDill

A badge is seen on a special backpack designed to monitor pollution during the COVID-19 lockdown on Clapham Common, London, Britain June 29, 2020. Picture taken June 29, 2020. REUTERS/Stuart McDill

A dog, carried in a protester's backpack, howls as demonstrators march at the Port of Oakland commemorating the end of slavery in Texas, two years after the 1863 Emancipation Proclamation freed slaves elsewhere in the country, known as Juneteenth, in Oakland, California, U.S., June 19, 2020. REUTERS/Nathan Frandino

Backpackers are seen in a street, amid the coronavirus disease (COVID-19) outbreak, in Venice, Italy June 19, 2020. REUTERS/Fabrizio Bensch

A sign is displayed next to a backpack during a vigil on the third anniversary of the death of Charleena Lyles, who was shot and killed in 2017 at her apartment by Seattle Police, at Magnuson Park in Seattle, Washington, U.S. June 18, 2020. REUTERS/Lindsey Wasson

A man is treated with milk from his own first aid backpack after being exposed to tear gas during a rally against racial inequality and the police shooting death of Rayshard Brooks, in Atlanta, Georgia, U.S. June 13, 2020. REUTERS/Elijah Nouvelage TPX IMAGES OF THE DAY

Motorbike taxi drivers prepare to strap on backpack-style plastic partitions to prevent the spread of coronavirus diseases (COVID-19) as they wait for customers in Jakarta, Indonesia, June 9, 2020. Picture taken June 9, 2020. REUTERS/Willy Kurniawan

A person stands on a social distancing sign painted on the pavement during a protest rally demanding the resignation of Czech's Prime Minister Andrej Babis, the sign on the backpack reads: "Mask is not a muzzle", following the coronavirus disease (COVID-19) outbreak, in Prague, Czech Republic June 9, 2020. REUTERS/David W Cerny

A shopping cart and backpacks mark people's places in a queue while they wait to receive donated food at San Ramon Nonato Catholic parish amid the coronavirus disease (COVID-19) outbreak in Madrid, Spain, June 2, 2020. REUTERS/Susana Vera

Giulio Giovannini, 12, with his mother Gloria, carries a backpack with a tablet, after traveling from his family cottage in the Tuscan countryside, where he has no internet signal, to the top of a hill where he is able to access the Internet to participate in online lessons while schools remain closed due to the spread of coronavirus disease (COVID-19), in Scansano, Italy, April 15, 2020. REUTERS/Jennifer Lorenzini

Giulio Giovannini, 12, and mother Gloria carry a backpack with a tablet, a small camping table and a chair as they travel from their family cottage in the Tuscan countryside, where he has no internet signal, to the top of a hill where he is able to access the Internet to participate in online lessons while schools remain closed due to the spread of coronavirus disease (COVID-19), in Scansano, Italy, April 15, 2020. REUTERS/Jennifer Lorenzini

Giulio Giovannini, 12, together with his mother Gloria, puts a backpack in the car with a tablet, a camping chair and a picnic table, to travel from his family cottage in the Tuscan countryside, where he has no internet signal, to the top of a hill where he is able to access the Internet to participate in online lessons while schools remain closed due to the spread of coronavirus disease (COVID-19), in Scansano, Italy, April 15 2020. REUTERS/Jennifer Lorenzini

Giulio Giovannini, 12, with his mother Gloria, prepares the backpack with a tablet, a small camping table and a chair, to travel from his family cottage in the Tuscan countryside, where he has no internet signal, to the top of a hill where he is able to access the Internet to participate in online lessons while schools remain closed due to the spread of coronavirus disease (COVID-19), in Scansano, Italy, April 15, 2020. REUTERS/Jennifer Lorenzini

Giulio Giovannini, 12, together with his mother Gloria, a backpack and a tablet, leaves the house to travel from his family cottage in the Tuscan countryside, where he has no internet signal, to the top of a hill where he is able to access the Internet to participate in online lessons while schools remain closed due to the spread of coronavirus disease (COVID-19), in Scansano, Italy, April 15, 2020. REUTERS/Jennifer Lorenzini

Backpacker and Spanish language student Lola Daehler, from the U.S., is pictured at a classroom after she decided to stay in Guatemala, where she feels safer to confront the outbreak of coronavirus disease (COVID-19), in San Pedro La Laguna, Solola, Guatemala March 27, 2020. Picture taken on March 27, 2020. REUTERS/Luis Echeverria

A general view of Pedro La Laguna, Guatemala, where backpacker and Spanish language student Lola Daehler from the U.S. has decided to stay as she feels safer to confront the outbreak of coronavirus disease (COVID-19), in San Pedro La Laguna, Solola, Guatemala March 27, 2020. Picture taken on March 27, 2020. REUTERS/Luis Echeverria

Backpacker and Spanish language student Lola Daehler, from the U.S., jumps into the water after she decided to stay in Guatemala, where she feels safer to confront the outbreak of coronavirus disease (COVID-19), in San Pedro La Laguna, Solola, Guatemala March 27, 2020. Picture taken on March 27, 2020. REUTERS/Luis Echeverria TPX IMAGES OF THE DAY

Backpacker and Spanish language student Lola Daehler, from the U.S., is pictured at a classroom after she decided to stay in Guatemala, where she feels safer to confront the outbreak of coronavirus disease (COVID-19), in San Pedro La Laguna, Solola, Guatemala March 27, 2020. Picture taken on March 27, 2020. REUTERS/Luis Echeverria

Backpacker and Spanish language student Lola Daehler, from the U.S., talks with her friend after she decided to stay in Guatemala, where she feels safer to confront the outbreak of coronavirus disease (COVID-19), in San Pedro La Laguna, Solola, Guatemala March 27, 2020. Picture taken on March 27, 2020. REUTERS/Luis Echeverria

Backpacker and Spanish language student Lola Daehler, from the U.S., is pictured at a classroom after she decided to stay in Guatemala, where she feels safer to confront the outbreak of coronavirus disease (COVID-19), in San Pedro La Laguna, Solola, Guatemala March 27, 2020. Picture taken on March 27, 2020. REUTERS/Luis Echeverria

Backpacker and Spanish language student Lola Daehler, from the U.S., is pictured at a classroom after she decided to stay in Guatemala, where she feels safer to confront the outbreak of coronavirus disease (COVID-19), in San Pedro La Laguna, Solola, Guatemala March 27, 2020. Picture taken on March 27, 2020. REUTERS/Luis Echeverria

An Uber Eats food delivery courier's backpack is seen in Paris during a lockdown imposed to slow the spread of the coronavirus disease (COVID-19) in France, France, April, 1, 2020. French supermarket retailer Carrefour and Uber Eats would launch a new delivery service aimed at helping Parisians buy essential goods and food during the nationwide lockdown triggered by the coronavirus crisis. REUTERS/Gonzalo Fuentes

An Uber Eats food delivery courier's backpack is seen in Paris during a lockdown imposed to slow the spread of the coronavirus disease (COVID-19) in France, France, April, 1, 2020. French supermarket retailer Carrefour and Uber Eats would launch a new delivery service aimed at helping Parisians buy essential goods and food during the nationwide lockdown triggered by the coronavirus crisis. REUTERS/Gonzalo Fuentes

A scooter driver of mobile app toters puts a delivery inside a courier's backpack amid the coronavirus disease (COVID-19) outbreak, in Beirut, Lebanon March 18, 2020. Picture taken March 18, 2020. REUTERS/Mohamed Azakir

An Uber Eats food delivery courier's backpack is seen in front of a fast food restaurant as the spread of coronavirus disease (COVID-19) continues in Amsterdam, Netherlands March 25, 2020. REUTERS/Eva Plevier

An Uber Eats food delivery courier packs his backpack as the spread of coronavirus disease (COVID-19) continues in Amsterdam, Netherlands March 25, 2020. REUTERS/Eva Plevier

A father carries the backpack of his daughter as he waits for her at entrance of a school after Catalonia announced to close schools, kindergartens, institutes and universities from tomorrow as a precaution against coronavirus in Barcelona, Spain March 12, 2020. REUTERS/Nacho Doce

A father carries the backpack of his daughter as they ride their bicycle home after Catalonia announced to close schools, kindergartens, institutes and universities from tomorrow as a precaution against coronavirus in Barcelona, Spain March 12, 2020. REUTERS/Nacho Doce

Backpacks of students are seen at a school after Catalonia announced to close schools, kindergartens, institutes and universities from tomorrow as a precaution against coronavirus in Barcelona, Spain March 12, 2020. REUTERS/Nacho Doce

A woman carries her pet cat inside of a backpack as she walks along a street in downtown Washington, U.S., March 11, 2020. REUTERS/Carlos Barria

A person wearing a U.S. Public Health Service backpack arrives with a group of people carrying medical scrubs at the Life Care Center of Kirkland, a long-term care facility linked to several confirmed coronavirus cases, in Kirkland, Washington, U.S. March 8, 2020. REUTERS/Lindsey Wasson

Raymond Determann, a King County Metro equipment service worker, wears a backpack that sprays a Virex solution to sanitize buses against the coronavirus in Seattle, Washington, U.S. March 5, 2020. REUTERS/Jason Redmond

Raymond Determann (L), a King County Metro equipment service worker, wears a backpack that sprays a Virex solution to sanitize buses against the coronavirus in Seattle, Washington, U.S. March 5, 2020. REUTERS/Jason Redmond

Kristen Curley, owner of Nitro-Pak, puts items into a backpack as part of personal protection and survival equipment kits ordered by customers preparing against novel coronavirus, at Nitro-Pak in Midway, Utah, U.S. February 27, 2020. REUTERS/George Frey REFILE - CORRECTING COMPANY NAME SPELLING

Kristen Curley, owner of Nitro-Pak, puts a dust & particle mask into a backpack as part of personal protection and survival equipment kits ordered by customers preparing against novel coronavirus, at Nitro-Pak in Midway, Utah, U.S. February 27, 2020. REUTERS/George Frey REFILE - CORRECTING COMPANY NAME SPELLING

Kristen Curley (R), owner of Nitro-Pak, and an employee, put items into a backpack as part of personal protection and survival equipment kits ordered by customers preparing against novel coronavirus, at Nitro-Pak in Midway, Utah, U.S. February 27, 2020. REUTERS/George Frey REFILE - CORRECTING COMPANY NAME SPELLING

Kristen Curley, owner of Nitro-Pak, puts a backpack on a shelf to be sold as one of the personal protection and survival equipment kits ordered by customers preparing against novel coronavirus, at Nitro-Pak in Midway, Utah, U.S. February 27, 2020. REUTERS/George Frey REFILE - CORRECTING COMPANY NAME SPELLING

Pins are pictured on the backpack of an activist of "Democrats Abroad" and supporter of Democratic U.S. presidential candidate Senator Bernie Sanders promoting the vote for U.S. citizens abroad, in Berlin, Germany, February 22, 2020. REUTERS/Michele Tantussi

Worker Gong Lixia helps her colleague Wang Fu to put on the disinfectant liquid backpack as they sanitise a residential compound, following an outbreak of the novel coronavirus in the country, in Beijing, China February 21, 2020. REUTERS/Tingshu Wang

A woman looks at backpacks made of hemp, recycled plastics and bottles from fishing nets at the booth of the company Vaude, during the ISPO trade fair for sports equipment and fashion in Munich, Germany, January 26, 2020. REUTERS/Michael Dalder

A woman looks at backpacks made of hemp, recycled plastics and bottles from fishing nets at the booth of the company Vaude, during the ISPO trade fair for sports equipment and fashion in Munich, Germany, January 26, 2020. REUTERS/Michael Dalder

A migrant travelling to the U.S. carries a chihuahua doll in his backpack at the border between Guatemala and Mexico, in Tecun Uman, Guatemala, January 18, 2020. REUTERS/Jose Cabezas

A Hong Kong protester wears a backpack with eye drops for use against tear gas and pepper spray during a Christmas Day rally in Sha Tin shopping mall in Hong Kong, China, December 25, 2019. REUTERS/Lucy Nicholson

Zoey Tiemann, 4, plays with her new backpack at her family's home in Seguin, Texas, U.S., June 2, 2019. Picture taken June 2, 2019. REUTERS/Callaghan O'Hare

A backpack with a logo of English soccer club Arsenal is seen at an Adidas store in Beijing, China December 16, 2019. REUTERS/Jason Lee

Zayleeana Tiemann, who recently turned 3, tries on her backpack before her first day of school in Seguin, Texas, U.S. August 22, 2019. REUTERS/Callaghan O'Hare SEARCH "US MATERNAL MORTALITY" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

A Turkey-backed Syrian rebel fighter carries a backpack and a weapon in the village of Yabisa, near the Turkish-Syrian border, Syria, October 13, 2019. REUTERS/Khalil Ashawi

A firefighter from Bolivia's army places backpacks on a pickup truck before patrolling an area where wildfires have destroyed hectares of forest at Rancho Grande village in Robore, Bolivia, September 24, 2019. REUTERS/Edgard Garrido

Residents fill plastic backpacks with water as they prepare to fight against wildfires in Santa Monica community in Concepcion, Bolivia, September 21, 2019. Picture taken September 21, 2019. REUTERS/Edgard Garrido

A resident carries a plastic backpack with water as he prepares to fight against wildfires in Concepcion, Bolivia, September 21, 2019. REUTERS/Edgard Garrido

Police officers check backpacks during a demonstration on Act 45 (the 45th consecutive national protest on Saturday) of the yellow vests movement in Paris, France, September 21, 2019. REUTERS/Pascal Rossignol

A boy shows the contents of his backpack to Haitian National Police (PNH) officers after a protest outside the facilities of the Parliament and the Senate in Port-au-Prince, Haiti, September 11, 2019. REUTERS/Andres Martinez Casares

A row of colorful backpacks belonging to first graders line the wall at Pinnacle Charter School during TAC*ONE training for an active shooter situation in a school in Thornton, Colorado, U.S. August 29, 2019. REUTERS/Rick Wilking

Shoes and backpack of Vans are seen in a shop window in Sao Paulo, Brazil August 29, 2019. REUTERS/Rahel Patrasso

Shoes and backpack of Vans are seen in a shop window in Sao Paulo, Brazil August 29, 2019. REUTERS/Rahel Patrasso

Shoes and backpack of Vans are seen in a shop window in Sao Paulo, Brazil August 29, 2019. REUTERS/Rahel Patrasso