Ключевые слова: abstract, background, black, blackboard, blank, board, button, chalk, chalkboard, computer, concept, conceptual, copy, copyspace, danger, dirty, drawing, education, engineering, firewall, grunge, handwriting, icon, internet, lock, message, net, network, pc, privacy, protect, protection, red, safe, safety, secret, secure, security, shield, sign, space, symbol, technology, text, texture, web, white, wooden, write, www,