4. For and Since

http://www.bnv-bamberg.de/home/ba4613/flg/englischinteraktiv/since-for-01.htm

3. For and Since

http://www.englisch-hilfen.de/en/exercises/since_for.htm

2. For and Since

http://www.englishclub.com/grammar/verbs-m_for-since_quiz.htm

For or Since

http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/upperf1.htm