— Have you found your English book? — I am not sure I could have left it.A. whetherB. wha

问题补充：

— Have you found your English book?

— I am not sure I could have left it.

A. whether

B. what

C. when

D. where

答案：

A. whether

B. what

C. when

D. where

解析：主要测试宾语从句。译文：---你已经找到你的英语书了吗？---我没有把握把它放哪儿了。