---Have you returned the book to the library ?---Yes I have retuned it.A. yet yetB. alr

问题补充：

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

---Yes, I have retuned it.

A. yet, yet

B. already, already

C. already, yet

D. yet, already

答案：

A. yet, yet

B. already, already

C. already, yet

(答案→)D. yet, already

解析：句意：你已经把书还了图书馆吗？是的，我已经归还了。yet用于疑问句，已经，用于否定句，还；already,用于肯定句，已经。故选D。