Professor Mann von der Universität oder Kollege blickt in die Kamera und zeigt auf seine Theorie, Konzept oder beweisen isoliert auf schwarzem Hintergrund im Studio. - Stockfoto & -bild

Portrait of handsome professor man of university or colleage isolated on black background. Teacger looking at camera in studio.

Portrait of handsome professor man of university or colleage posing with his arms crossed or folded isolated on black background in studio.

Portrait of serious professor man looking at camera isolated on black background. Handsome teacher of university or colleage in studio.

Picture of handsome professor man of university or colleage explaining material in studio. Teacher holding pen and looking at camera.

Picture of professor man of university or colleage having lecture in studio. Experienced teacher explaining material to students or pupils.

Picture of professor man of university or colleage having lecture or practical class or lesson. Man explaining material to students or pupils in studio.

Portrait of professor man of university or colleage posing with his eyes closed in studio. Teacher in business suit touching his face isolated on black background.

Picture of demanding professor man of university or colleage isolated on black background. Mature teacher posing with clipboard and looking at camera in studio.

Businessman making different pictures. Mature man in business suit happy focusing on photographer isolated on cream bcakground.

Serious businessman posing with yellow flashlight in his hand. Middle-haired man in black business suit is going to clear up the situation.

Smiling businessman keeping black camera isolated on dark grey. Man with blond hair in black business suit is very successful in company.

Profile of hipster bearded businessman in glasses. Bold man in black business suit grinning with delight on dark background.

Mature handsome man with grey beard looking thoughtful at the camera wearing casual jacket and jeans holding hands in pockets.

Mature handsome man with grey beard looking up leaning on tree wearing casual grey jacket. Life after 40 years concept, problems and depression. Middle age crisis.

Serious bearded man pointing out on black background. Bold man in straw hat frowning, because of annoyance.

Middle-haired businessman smiling in red boxing gloves. Young man in sunglasses ready to compete with his business rivals.

Portrait of bearded man fooling on dark grey. Bold man in straw hat blowing on his fingers.

Confident businessman sitting on chair and showing okay gesture. He is sitting with crossing legds on the chair in the office.He has a wide bright smile on his face. He is wearing a black suit and a

Handsome mature businessman posing with register in his hands. Man in grey business suit going to represent new business strategy.

Hipster bearded man looking like matrix. Bold man in black sunglasses making fingers like pistol on dark grey background.