1 ex.
1) was flying
2) were waiting
3) were crossing
4) were playing
5) was washing
6) was cooking
7) was slicing
8) was jumping
2 ex.
1) broke
2) was going
3) saw
4) was having
5) met
6) was cooking
7) took
8) lost
3 ex.
1) came/were playing
2) was turning on/happened
3) was walking/saw
4) were running/fell over
5) got/was going
6) was drinking/dropped
7) was listening/heard