Comparative

http://www.englishexercises.org/makeagame/viewgame.asp?id=2596
http://www.learnenglish-online.com/grammar/tests/comparativeadjectives2.html
http://www.better-english.com/grammar/comparatives.htm
http://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjectives_comparison_sentences.htm