Поставьте следующие предложения в прошедшем и будущем времени, изменив соответственно обстоятельства времени.
1. Our students are given a lot of homework to do every day.
2. What kind of books are discussed in class?
3. Comrade Ivanov is often asked to translate articles from English into Russian.
4. How many houses are built in our city a year?
5. Why aren't these exercises done?