Comparatives+exercises+(once)

group 1 : http://www.englishexercises.org/makeagame/viewgame.asp?id=7493

group 2: http://www.englishexercises.org/makeagame/viewgame.asp?id=5373

group 3: http://www.englishexercises.org/makeagame/viewgame.asp?id=7232

group 4: http://www.englishexercises.org/makeagame/viewgame.asp?id=6785