http://www.engvid.com/adjective-endings-ing-ed/#quiz
http://learnenglish.britishcouncil.org/en/english-grammar/adjectives/adjectives-ed-and-ing
http://learnenglish.britishcouncil.org/en/grammar-exercises/adjectives-ending-ed-and-ing
http://www.theenglishstudent.com/blog/participial-adjectives
http://www.trussel.com/eding.htm
http://a4esl.org/q/h/9801/dg-eding.html
http://www.better-english.com/grammar/adjing.htm
http://www.englishexercises.org/makeagame/viewgame.asp?id=2255
