Раскройте скобки,употребив глаголы в нужной видовременной форме. last sunday one of my friends (to celebrate) his birthday.when i (to arrive),i (to see) that his flat (to be) full of guests.i (to enter) the living room.some people (to dance).several guests (to sing) a merry song and the hostess (хозяйка дома) (to play) the piano.a group of girls (to listen) to music and other people (to watch) the telrlevision.my friend (to introduce) me to his guests when the hostess (to invite) everybody to the table.the party ended late in the evening.i had a very good time there.

Last Sunday one of my friends  celebrated his birthday.When I  arrived,I  saw that his flat was full of guests.I entered the living room.Some people were dancing.Several guests were singing a merry song and the hostess (хозяйка дома) was playing the piano.A group of girls were listening to music and other people were watching the telrlevision.My friend was introducing me to his guests when the hostess  invited everybody to the table.The party ended late in the evening.I had a very good time there.