6.Choose the cjrrect verb form.
Dmitry and Omar have been to Astana.
a)They have seen/saw the tower "Baiterek".
b)They saw/ have seen the concert last week.
c)They love Rock and Roll.I like /have liked it all my life.
d)They bought / have bought a lot of interesting books after the concert.
e)They stayed / have stayed in Astana since October.
f)They know / have known each other for 5 years.
g)When did they go / have they done to Astana&
h)Dmitry went / has done to Astsns 3 months ago.
i)Omar lived / has lived there for 5 months.

Заранее спасибо