Lecture with formulas on the blackboard in front of studentsLecture with formulas on the blackboard in front of students
A gray block of rock on the shore, against the background of a lilac skyA gray block of rock on the shore, against the background of a lilac sky
Waiting for the way on the background of autumn treesWaiting for the way on the background of autumn trees
The road among the fields on the background of sunsetThe road among the fields on the background of sunset
The rays of the sun fall on the leaves of the treesThe rays of the sun fall on the leaves of the trees