Ответ:

1.  We have seen everything in this museum.

2. I don`t like this park. It is very small.

3. What a nice hat you have! When did you buy it? - I bought it last month.

4. Will you sing at the party?

5. Where are you going? - I am going to the station.

6. Where are you from? - I am from Moscow.

7. I have done my home-work - I am free now.

8. Nick has bought a very good present for his mother.