Напишите три предложения изменяя его отрицательные и положительные и вопросительной форме в past perfect continuous.

1 They had been skating together for 7 years before they took part in the competition.

They hadn't been skating together for 7 years before they took part in the competition.

Had they been skating together for 7 years before they took part in the competition?

2 We had been picking apples the whole day so we were tired.

We hadn't been picking up apples the whole day, so we weren't tired

Had we been picking up apples the whole day, so we were tired!

3 Sam had been working here for 2 years before he left to go to the university.

Sam hadn't been working here for 2 years before he left to go to the university.

Had Sam been working here for 2 years before he left to go to the university?