http://www.focus.olsztyn.pl/en-present-perfect-tense-exercises-with-answers.html#.X0-o6twzbIU

http://www.adelescorner.org/grammar/pres_perfect/pres_perfect_1.html

http://www.focus.olsztyn.pl/en-exercise-on-present-perfect-tense.html#.X0-pKNwzbIU