Active and Passive voice - Exercises on line to practice

http://www.ego4u.com/en/cram-up/grammar/question-tags/exercises
http://www.ego4u.com/en/cram-up/grammar/question-tags/exercises
http://www.ego4u.com/en/cram-up/grammar/question-tags/exerciseswww.englisch-hilfen.de/en/exercises/active_passive/active_or_passive.htm
http://www.ego4u.com/en/cram-up/grammar/question-tags/exerciseswww.englisch-hilfen.de/en/exercises/active_passive/active_or_passive.htm
http://www.ego4u.com/en/cram-up/grammar/question-tags/exerciseswww.englisch-hilfen.de/en/exercises/active_passive/active_or_passive.htm