Lecture with formulas on the blackboard in front of studentsLecture with formulas on the blackboard in front of students
A big tree and small trees in the distance in the fieldA big tree and small trees in the distance in the field
Dawn from behind the mountains in the nature reserve with a treeDawn from behind the mountains in the nature reserve with a tree
Painting a house in winter in the forest in the darkPainting a house in winter in the forest in the dark