1) 1-e; 2-d; 3-f; 4-c; 5-a; 6-b.
2) 2. Did people ride to work in 1990? Yes, they did.
3. Did people watch TV in 1990? No, they didn't.
4. Did people be in space? No, they didn't.
5. Did people ski in the mountains? Yes, they did.
3) 2. had; 3. took; 4.; went; 5. bought; 6. had; 7. saw; 8. was; 9. leaved (не помню как будет 2 форма этого глагола); 10. got; 11. watched; 12. went.