2. Complete the sentences. Поставь глаголы в скобках в Past Perfect Continuous: 1) Before the experiment ended, the scientists ___ (work) for six hours. 2) He ___ (study) mathematics since he was a child. 3) They ___ (not / use) the new method for long. 4) ___ she ___ (write) her report before the meeting?

Перевод задания: Дополните предложения, поставив глаголы в скобках в Past Perfect Continuous.

1. Before the experiment ended, the scientists had been working for six hours.
   Перевод: До окончания эксперимента учёные работали уже шесть часов.
2. He had been studying mathematics since he was a child.
   Перевод: Он изучал математику с детства.
3. They had not been using the new method for long.
   Перевод: Они недолго использовали новый метод.
4. Had she been writing her report before the meeting?
   Перевод: Писала ли она свой доклад до собрания?

Формула: had been + глагол с окончанием -ing; в отрицании — had not been, в вопросе Had ставится перед подлежащим.