Нужно раскрыть скобки: when the director of the hermitage (to ask) how the museum (to get) such a big collection, he (to answer): “the history of our museum (to begin) in 1764 when 225 paintings (to purchase) in the west by catherine the great. the collection (to grow) in size from year to year since then. after the revolution a lot of splendid pieces of art (to come) to the museum from private collections”.
Was asked
Got
Answered
Began
Were purchased
Had been growing
Came