Ответ:

2) What's the shortest word on this page?

3) Which is the most interesting text in units 1-6 of this book?

4) Which is the best exercise on this page?

5) Whats the most difficult grammar point in English?

6) who is the happiest person in your family?

7) who is the most friendly person in your English class?

8) which is the worst restaurant in your town?