mixed exercises in present perfect

http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises

present perfect: never

http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises?06

present perfect: have/has

http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises?03

for/since/yet/already: present perfect

http://perso.wanadoo.es/autoEnglish/gr.since.i.htm

yet/already: present perfect

http://www.more-online.it/more3/u02/present_perfect/asp.html

choose the correct verb: present perfect

http://www.english-grammar-lessons.com/presentperfect/exercise1.swf

Have you ever...? Present perfect

http://www.kico4u.de/english/uebungen/6klasse/ever.htm

present perfect: ever/never

http://www.1-language.com/englishcoursenew/unit52_grammar_exs.htm

present perfect

http://www.kico4u.de/english/uebungen/aktiv/presentperfect.htm