IntheUnitedStates,childrenstartschoolwhentheyarefiveyea...
问题详情：IntheUnitedStates,childrenstartschoolwhentheyarefiveyearsold.Insomestatestheymuststayinschooluntiltheyaresixteen.Moststudentsareseventeenoreighteenyearsoldwhentheyleavesecondary（中等的）schools.T...