Mary felt sad over the loss of photos she had shot in Australia that was a memory she es

问题补充：

Mary felt sad over the loss of photos she had shot in Australia, that was a memory she especially treasured.

A. as

B. which

C. when

D. where

答案：

(答案→)A. as

B. which

C. when

D. where

解析：A。这题考查as引导原因状语从句。句意为：玛丽对她丢失了在澳洲拍的照片感到很悲伤，因为那是她最珍贵的记忆。