Exercises (Simple Present)

https://www.ego4u.com/en/cram-up/tests/simple-present-1
http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/pres1.htm
http://www.really-learn-english.com/simple-present-exercises.html#05
http://www.englishexercises.org/makeagame/viewgame.asp?id=1555
http://www.englisch-hilfen.de/en/exercises_list/zeitformen.htm