RELATIVES

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-62912.php

http://www.ego4u.com/en/cram-up/grammar/relative-clauses/exercises?02

http://www.ego4u.com/en/read-on/countries/uk/tour/stonehenge#exercises

http://www.englishexercises.org/makeagame/viewgame.asp?id=872