1 .......had been watching the building for an hour.......

2 .........had been studying it since 2001

3 ........had been working since 5 a.m.......

4 We had been living here since 2007.......

5 The telephone had been ringing for five minutes...........

6 .......had been feeling unwell for two weeks..........

7 Lucy had e playing the piano since she was a child.