please fill the answer?

sy jawab yang bawah saja ya. karena yang atas tidak jelas intruksinya apa.

we must pay the bill
- we must not pay the bill.
? must we pay the bill?

I lost the book two days ago
- I didn't lose the book two days ago
- did i lose the book two days ago?

he knows the answer
- he doesn't know the answer.
- does he know the answer?