Grammar : Verb TO BE

PRACTISE THE VERB  ´TO BE´ IN ALL ITS FORMS: POSITIVE, NEGATIVE AND ANSWER! :) 

1)http://www.agendaweb.org/verbs/tobe/
2)http://activiscope.com/flash_new.php?activity=catchoice&id=21435
3)http://www.web-esl.com/tobe/tobe20.htm
4) http://baladre.info/english/sedaviwebfront/beinterrogative.htm