1)how long has duman been living/does he live in astana? 2)how long has omar been studying/does he study at school 15? 3)my friend has been looking/looked for a bike for 3 weeks 4)i wrote/have been writing this exercise since 4 o'clock pm.

A)How long has Dmitry been living in Astana ?
b)How long has Omar been studying at school №15
c)My friends has been looking for a bike for 3 week
d)I have been writing this exersise since 4 o*clock
e)I am tired because i have been writing this exersice since 4 o*clock