Giovane studente o insegnante premuroso in piedi di fronte a una lavagna con note che fissano di lato di profilo con un'espressione contemplativa, primo piano colpo alla testa - Foto e immagini stock

Businesswoman or teacher pondering a problem standing looking away from the camera at a blurred blackboard full of notes and calculations

A good asian teacher writing on blackboard with chalk in classroom

Woman scientist or student working with various high school maths and science formula standing on gray background.

A good asian teacher writing on blackboard with chalk in classroom

A beautiful lady is dreaming about graduation. Math formulas, an arrow, geometric figures are drawn on the black chalkboard.

Portrait of thoughtful female student standing in classroom

Sensual student woman is standing with chalk board behind her

Young female teacher looking at invisible product against chalkboard

Young woman standing in profile writing with chalk on a blackboard in a classroom

Problem solving young student in class room

Portrait of woman looking at the green board in a side view shot

Blond student looking at the green board in classroom

Attractive young female student standing solving a problem staring thoughtfully up into the air with her finger to her lips against a blank green blackboard with copyspace

Young woman sitting in front of the blackboard and thinking about something.

Side view of a thoughtful young blond woman in front of chalkboard

Young female student in maths class trying to solve a problem standing with her back to the blackboard staring thoughtfully into the air

Young bemused Asian student seeking an answer staring at a blank green chalkboard with her hand to her lips and a bewildered expression