(seasons): http://sheppardsoftware.com/scienceforkids/seasons/seasons.htm
(life cycles): http://sheppardsoftware.com/scienceforkids/life_cycle/index.htm
(dinosaurs): http://sheppardsoftware.com/scienceforkids/dinosaurs/dinosaurs.htm
(sea creatures): http://sheppardsoftware.com/content/animals/profile_deepsea.htm