Lecture with formulas on the blackboard in front of studentsLecture with formulas on the blackboard in front of students
Waiting for the way on the background of autumn treesWaiting for the way on the background of autumn trees
A field of pink cosmos on the background of mountains and cloudsA field of pink cosmos on the background of mountains and clouds
The rays of the sun fall on the leaves of the treesThe rays of the sun fall on the leaves of the trees
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