évszámok, fogalmak: https://quizlet.com/167652979/flashcards
http://www.classtools.net/connect/201611_BB3UER
http://www.classtools.net/widgets/venn_2circle_5/6bRTw.htm
https://learningapps.org/display?v=pmiz9kvnj01
https://learningapps.org/2912903
próbadolgozat: https://redmenta.com/?solve&ks_id=366860580