Children are seen washing their hands at Heath Mount School as some schools reopen, following the outbreak of the coronavirus disease (COVID-19), Watton-at-Stone, Britain, June 2, 2020.

Year 6 children sit at their desks as they are taught at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

Children queue to enter the lunch hall at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

A year 6 child puts his hand up to answer during class at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020. Image for illustrative purposes.

Image used for illustrative purpose. A year six pupil has his temperature checked by a member of staff at St John's Primary School as some children returned to the school as the coronavirus disease (COVID-19) lockdown eases in Fulham, West London, Britain, June 2, 2020.

Parents and children arrive at Watlington Primary School as some schools re-open, following the outbreak of the coronavirus disease (COVID-19), Watlington, Britain, June 1, 2020.

A child plays with a hoop at Watlington Primary School as some schools re-open, following the outbreak of the coronavirus disease (COVID-19), Watlington, Britain, June 1, 2020.

Children queue to enter the lunch hall at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

Children take part in sports lessons at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

A year six pupil has her temperature checked by head teacher Barbara Wightwick at St John's Primary School as some children returned to the school as the coronavirus disease (COVID-19) lockdown eases in Fulham, West London, Britain, June 2, 2020.

A year six pupils arrive at St John's Primary School as some children returned to the school as the coronavirus disease (COVID-19) lockdown eases in Fulham, West London, Britain, June 2, 2020.

Children are seen in a classroom at Watlington Primary School as some schools re-open, following the outbreak of the coronavirus disease (COVID-19), Watlington, Britain, June 1, 2020.

A child carries his food during lunch break at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

Children take part in sports lessons at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

A boy stands by a red line at Watlington Primary School as some schools re-open, following the outbreak of the coronavirus disease (COVID-19), Watlington, Britain, June 1, 2020.

Children during a class at Heath Mount School as some schools reopen, following the outbreak of the coronavirus disease (COVID-19), Watton-at-Stone, Britain, June 2, 2020.

A child doing arts and crafts at Watlington Primary School as some schools re-open, following the outbreak of the coronavirus disease (COVID-19), Watlington, Britain, June 1, 2020.

Year 6 children sit at their desks as they are taught at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

Children of key workers eat their lunch at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

Children are seen washing their hands at Heath Mount School as some schools reopen, following the outbreak of the coronavirus disease (COVID-19), Watton-at-Stone, Britain, June 2, 2020.

Children chat on a break at Heath Mount School as some schools reopen, following the outbreak of the coronavirus disease (COVID-19), Watton-at-Stone, Britain, June 2, 2020.

Children are seen in a classroom at Watlington Primary School as some schools re-open, following the outbreak of the coronavirus disease (COVID-19), Watlington, Britain, June 1, 2020.

Image used for illustrative purpose A teacher talks to a child at Watlington Primary School as some schools re-open, following the outbreak of the coronavirus disease (COVID-19), Watlington, Britain, June 1, 2020.

A child carries his food during lunch break at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

Year 6 children sit at their desks as they are taught at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

Children eat their lunch at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

A year six pupil has her temperature checked by a member of staff at St John's Primary School as some children returned to the school as the coronavirus disease (COVID-19) lockdown eases in Fulham, West London, Britain, June 2, 2020.

A teacher talks to a child during a class at Heath Mount School as some schools reopen, following the outbreak of the coronavirus disease (COVID-19), Watton-at-Stone, Britain, June 2, 2020.

Children are seen at Watlington Primary School as some schools re-open, following the outbreak of the coronavirus disease (COVID-19), Watlington, Britain, June 1, 2020.

Pupils queue to get into their classrooms at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

A child carries his food during lunch break at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.

Children eat their lunch at St Dunstan's College junior school as some schools re-open following the outbreak of the coronavirus disease (COVID-19) in London, Britain June 1, 2020.