Вставьте правильную форму глагола to be в предложениях

1. What were you doing: I was watching; 2. She was studying; 3. did the post arrive; It came while I was having;1. I was 10, so now I am; 2. is nice, but yesterday it was; 3. I am hungry; 4. I was very tired; 5. we were being; 6. they are very expensive.