Choose the correct verb form.
a) How long has Dmitry been living /does he live/ in Astana?

b) How long has Omar been styding / does he study/ at school 15 .

C) My friend has been looking/looked for a bike for 3 weeks

d) I wrote/ have been writing/ this exercise since 4 o clock p.m

e) I am tired because i wrote/ have been writing/ this exercise since 4 o clock p.m.

F) My friend is working /has been working / as an air hostees since last mouth.

g) I have bought/ bought/ a dictionary a few months ago