I.XII.71.1 Maintenance; double sessions; subjects; twelve-month school year"Every town shall maintain, for at least the number of days required by the board of education in each school year unless specifically exempted as to any one year by said board, a sufficient number of schools for the instruction of all children who may legally attend a public school therein. No town shall hold double sessions in any public school, if in any other public school of comparable grade levels in such town there are vacant spaces for more than thirty-five children, the number of such vacant spaces to be computed without exceeding a maximum of thirty-five children to a classroom."