Palestrante sênior feliz segurando avião de papel na mão - Banco de fotos e imagens

Pensive grey hair professor standing at blackboard with piece of chalk

Grey hair professor pointing on something with finger at blackboard

Grey hair professor looking at students rising hands

Grey hair professor pointing on something with wooden pointer

Happy senior lecturer with open arms standing near blackboard

Grey hair professor pointing on something with pencil on blackboard

Tired grey hair professor touching eyes at blackboard

Grey hair professor correcting something at blackboard

Grey hair professor holding stack of books with apple on top

Cropped image of senior professor pointing on something with pencil on blackboard

Cropped image of professor drawing with piece of chalk at blackboard

Excited senior man in bow tie and jacket holding smartphone isolated on grey

Cropped view of man with chalk writing numbers on blackboard

Cheerful schoolchild adjusting eyeglasses near chalkboard with mathematic equations

Handsome grey hair man sitting at table with chessboard and looking at camera

African american teacher writing on notebook near globe in classroom

Smiling elderly man looking at camera while holding laptop isolated on grey