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

问题补充：

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

答案：

A. yet, yet

B. already, already

C. already, yet

(答案→)D. yet, already

解析：句意：---你把书还给图书馆了吗？---是的。我已经还了。yet常用于现在完成时的否定或疑问句中, already用于肯定句中。结合语境可知选D。