Поставьте следующие предложения в прошедшее и будущее время, используя подходящий эквивалент модальных глаголов: 1) They can study many languages at our academy. 2) He may watch this project. 3) These problems must be solved.

1) They were able to study many languages at our academy. They will be able to study many languages at our academy. 2) He was allowed to watch this project. He will be allowed to watch this project. 3) These problems were to be solved. These problems had to be solved. These problems will have to be solved.