You can use the exercises below to practice before the short grammar test on Present Tenses:
http://www.ego4u.com/en/cram-up/grammar/simpre-prepro
http://www.englishexercises.org/makeagame/viewgame.asp?id=1438#a
http://www.e-ang.pl/test,75,Present_Simple_Present_Continuous.html
http://www.englishpage.com/verbpage/verbs1.htm
https://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises