ответ:1)has worked
2)has worked, for
3)have known, since
4)have known, for
5)has walked, for
6)has had, since
7)hasn't been, since
8)hasn't been, for
9)have had, since
10)have had, for
11)has improved
12)have had, for
13)don't work
14 )have attended, for
Объяснение:for - в течении какого-то периода, since - с какого-то времени
