present and past continious

http://www.englishexercises.org/makeagame/viewgame.asp?id=2935
http://www.englishpage.com/verbpage/pastcontinuous.html
http://www.leshoekje.be/leshoekje/ICT-oef%20ENG2/present-past3.htm
http://www.englisch-hilfen.de/en/grammar/past_progressive_verbs.htm