While Jane ... Christmas tree, her mum ... the room.
Укажите правильный вариант ответа:
was decorating, was cleaning
decorated, was cleaning
was decorating, cleaned
decorated, cleaned

Ответ:

While Jane was decorating Christmas tree, her mum cleaned the room.

Объяснение:

When we use these (Past Simple and Past contunious) two tenses together, it shows us that the past simple action happened in the middle of the past continuous action, while it was in progress.   For example: While I was studying, I suddenly felt sleepy.