Ключевые слова: background, basic, challenge, choice, color, concept, conceptual, connect, connection, current, difficulty, educate, enlarge, fit, fundamental, game, glass, group, handle, idea, information, issue, jigsaw, join, layer, leisure, lens, magnify, magnifying, missing, object, part, pattern, piece, puzzle, red, rights, scrutinize, set, shape, solution, solve, strategy, surface, topic, toy, white, words,