Put the verbs in brackets in the correct passive tense. The largest multi-purpose room on the premises is the Ballroom. It 5) (open) in 1856 with a ball to celebrate the end of the Crimean War, and since then, it 6) (use) as a concert hall for various arts performances.

Пошаговое решение:

• 5. (open): Цифра '1856' указывает на прошлое время. Глагол 'open' в Past Simple Passive будет 'was opened'.
• 6. (use): Фраза 'since then' указывает на действие, начавшееся в прошлом и продолжающееся. Глагол 'use' в Present Perfect Passive будет 'has been used'.

Ответ: 5) was opened, 6) has been used