Please help ... Срочнооо помогите пожалуйста. :)

Ответ:

2. came, were having 3. opened, were dancing 4. found, was cleaning 5. were waiting, started 6. was teaching, heard 7. called, were taking

Объяснение:

Past Simple - в основном после when

Past Continuous - всегда после while, и когда есть точное указание времени (в 7 часов вчера, целый вечер в понедельник, когда мама пришла)