tercer b

http://michel.barbot.pagesperso-orange.fr/hotpot/pronoms/pron1.htm
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-3074.php
http://www.englishexercises.org/makeagame/viewgame.asp?id=1965
http://baladre.info/english/sedaviwebfront/pronouns3.htm
http://www.englishexercises.org/makeagame/viewgame.asp?id=2873
http://www.englishexercises.org/makeagame/viewgame.asp?id=999