1. Spot the form. Подчеркни форму Past Perfect Continuous в предложениях и переведи предложения: 1) Mendeleev had been working on his table for months. 2) By the time the lecture began, the students had been reading about famous scientists. 3) She had been doing research since Monday.

Перевод задания: Найдите форму Past Perfect Continuous в предложениях.

1. Mendeleev had been working on his table for months. — Менделеев несколько месяцев работал над своей таблицей.
2. By the time the lecture began, the students had been reading about famous scientists. — К началу лекции студенты уже некоторое время читали об известных учёных.
3. She had been doing research since Monday. — Она проводила исследование с понедельника.

Формула: had been + глагол с окончанием -ing.