Three of them, in 1777, 1824 and 1924 were catastrophic. Ever since the foundation of the city by Peter the Great in 1703 various schemes for its protection were offered by specialists. But only due to modern technol¬ogy such a giant hydroengineering project was made possible.
Можно еще одну помощь по этому отрывку из текста? проанализирование глаголов на время и залог.. Пожалуйста..