1
1) had
2) were having
3) arrived
4) was waiting
5) were staying
6) were beating
7) were sitting and 8) dancing
9) was getting
10) could hear
11) was
2
1) They were sitting in the garden when it started to rain.
2) He was driving to work when he had an accident.
3) The telephone rang while I was having my dinner.
4) I was playing football when I hurt my nose.
5) Tony was walking in the park when he met Jackie.