Make up sentences.
I was cleaning the room when she rang

I was cleaning the room when she rang me. (Я убирался в комнате, когда она мне позвонила)
Tim was using a computer when I came in. (Тим сидел за компьютером, когда я вошёл)
The girl was walking in the park the whole evening. (Девченка гуляла в парке весь вечер)
We were talking about future an hour ago. (Мы сказали о будущем час вспять)
His parents were playing chess when the guests arrived. (Его родители играли в шахматы, когда прибыли гости)
The astronauts were speaking English at 2 p.m. yesterday. (Астронавты говорили по-английски вчера в два часа дня)