Do you remember your school years? what color were the desks, chairs, and blackboardDo you remember your school years? What color were the desks, chairs, and blackboard
On a dark gray blackboard, many mathematical formulas are written in chalkOn a dark gray blackboard, many mathematical formulas are written in chalk
A lot of white men are sitting at a desk in front of the blackboardA lot of white men are sitting at a desk in front of the blackboard
Lecture with formulas on the blackboard in front of studentsLecture with formulas on the blackboard in front of students
A teacher standing at the blackboard with a textbookA teacher standing at the blackboard with a textbook
An empty school classroom with desks and a blackboardAn empty school classroom with desks and a blackboard