Portuguese soldiers wearing protective gear disinfect a high school in Lisbon, Portugal, on April 29, 2020. Members of the country's armed forces carried out the disinfection of schools in preparation for a resumption of high schools. (Photo by Pedro Fiuza/Xinhua)

A Portuguese soldier wearing protective gear disinfects a high school in Lisbon, Portugal, on April 29, 2020. Members of the country's armed forces carried out the disinfection of schools in preparation for a resumption of high schools. (Photo by Pedro Fiuza/Xinhua)

Portuguese soldiers wearing protective gear prepare to disinfect a high school in Lisbon, Portugal, on April 29, 2020. Members of the country's armed forces carried out the disinfection of schools in preparation for a resumption of high schools. (Photo by Pedro Fiuza/Xinhua)

Portuguese soldiers wearing protective gear disinfect a high school in Lisbon, Portugal, on April 29, 2020. Members of the country's armed forces carried out the disinfection of schools in preparation for a resumption of high schools. (Photo by Pedro Fiuza/Xinhua)

Portuguese soldiers wearing protective gear disinfect a high school in Lisbon, Portugal, on April 29, 2020. Members of the country's armed forces carried out the disinfection of schools in preparation for a resumption of high schools. (Photo by Pedro Fiuza/Xinhua)

Portuguese soldiers wearing protective gear prepare to disinfect a high school in Lisbon, Portugal, on April 29, 2020. Members of the country's armed forces carried out the disinfection of schools in preparation for a resumption of high schools. (Photo by Pedro Fiuza/Xinhua)

Portuguese soldiers wearing protective gear prepare to disinfect a high school in Lisbon, Portugal, on April 29, 2020. Members of the country's armed forces carried out the disinfection of schools in preparation for a resumption of high schools. (Photo by Pedro Fiuza/Xinhua)