ESL and ELL websites
http://www.englishactivities.net/
http://www.learn-english-today.com/lessons/lesson_contents/exercises/a-an-the_quiz1.htm -- a, an, the
http://www.learn-english-today.com/lessons/lesson_contents/exercises/at-on-in_quiz1.htm -- at, on, in
http://www.learn-english-today.com/lessons/lesson_contents/exercises/ph-verb_put1.htm verb: put