Ключевые слова: 20, 80, analysis, art, artistic, background, board, business, chalk, chalkboard, chart, child, childhood, class, classroom, clean, closeup, concept, copy, data, design, draw, drawing, economy, education, eighty, elementary, factor, female, few, finance, financial, green, grunge, hand, idea, job, law, leisure, majority, market, marketing, message, minority, note, notice, number, office, pareto, percent, percentage, person, piece, plan, portion, principle, profit, quota, report, representation, result, rule, school, schoolchild, space, sparsity, statistics, stick, student, surface, survey, teacher, text, texture, twenty, vital, white, woman, work, writing,