Download
Close

Автор:
id:
Ключевые слова:
a, act, at, background, bill, black, blackboard, board, calculation, calculus, chalk, chalkboard, children39, class, classroom, college, complex, concept, drawing, education, elementary, equations, focus, formula, frame, government, hand, handwriting, high, illustration, isolated, kids, knowledge, learn, limited, on, one, s, school, smart, subject, symbol, teach, teacher, text, texture, time, white, word, writing,