Professor at Blackboard — Green

1600 × 1200

Professor Teaching Class — Black, Academic

1600 × 900

Professor Teaching Class — Black

1920 × 1079

Professor at Blackboard

1680 × 1050

Professor Teaching Class — Black, Academic, Photograph

1920 × 1060

Professor teaching in a lecture hall

1680 × 1050

Professor teaching in a lecture hall

1920 × 1080

Professor in Classroom — White

1920 × 1200

Professor teaching in a classroom

1920 × 1200

Professor Teaching Class — Black, Academic, Photograph, Blackboard, Students

1920 × 1200

Professor Teaching Class — Black, Academic, Photograph, Blackboard

1600 × 1000

Professor teaching in a lecture hall

2560 × 1600