---Have you returned the book to the library ____?   

---Yes, I have ____ returned it.

1. A.
   yet, yet
2. B.
   already, already
3. C.
   already, yet
4. D.
   yet, already

––Have you returned the book to the library _______? 
––Yes, I have _________ returned it.

––Have you returned the book to the library _______? 

––Yes, I have _________ returned it.

A．yet, yet           B．already, already     C．already, yet        D．yet, already

---Have you returned the book to the library ____?  ---Yes, I have ____ returned it.