http://www.english-zone.com/grammar/questions2.htm
http://a4esl.org/q/f/z/zz87mca.htm
http://a4esl.org/q/j/ck/fb-queswords.html
http://www.learnenglish.org.uk/words/activities/question_words01.html
http://www.1-language.com/englishcourse/unit7_index.htm
http://www.oup.com/elt/global/products/headway/preintermediate/a_grammar/unit01/hwy_preint_unit01_2/