On a dark gray blackboard, many mathematical formulas are written in chalkOn a dark gray blackboard, many mathematical formulas are written in chalk
A playing field with green grass and a drawing with chalkA playing field with green grass and a drawing with chalk
The inscription on the blue board with the old chalkThe inscription on the blue board with the old chalk
On the asphalt, figures are drawn in chalk, which are held by a guy and a girlOn the asphalt, figures are drawn in chalk, which are held by a guy and a girl