PREPOSITIONS

http://www.isabelperez.com/prepositions-1.htm

http://www.ego4u.com/en/cram-up/grammar/prepositions

http://www.englishpage.com/prepositions/prepositions.html

http://www.englisch-hilfen.de/en/exercises/preposition_room1.htm

http://esl.about.com/library/quiz/blgrquiz_prep3.htm