I think the school day should not go until 5pm.Firstly because if they had after school activities you would miss them.Secondly they would have to have dinner late.Finally it might be hard for their parents to get there at that time.
Firstly they would miss any after school activities they might have Which means you wouldn't get any exercise.Which means you could also get obese and unhealthy which would lead to high blood preasure.It could also lead to 1 kind of heart disease and 2 kinds of diabities.And if you try and exercies while obsese it will stress your joints.
Secondly you would have to have dinner late which would mean you would not be able to learn and you would also go to bed without food which could also mean you would not be eating like you regularly should be.And a child can last 35 hours but you can only 1 hour without wanting food.
Thirdly It could be hard for the parents to get there at that time which means it could be dangerous for the child to walk home at 5pm And also you should be over 13 to walk around by yourself at that time.
So personally I think that kids should not be left at school until 5pm.
