Question

Nina (to celebrate) her birthday yesterday. Her room looked beautiful, there (to be) many flowers in it. When I (to come) in, somebody (to play) the piano, two or three pairs (to dance).

Answer 1

Celebrated
Was
Come, was playing, were dancing

Answer 2

Nina celebrated her birthday yesterday. Her room looked beautiful, there are many flowers in it. When I came in, somebody played the piano,two or three pairs danced.