---Who left the window ?- Sorry. I forgot it when I left yesterday.A. opened; to closeB

问题补充：

---Who left the window ?

--- Sorry. I forgot it when I left yesterday.

A. opened; to close

B. open; to close

C. open; closing

D. opening; closing

答案：

A. opened; to close

(答案→)B. open; to close

C. open; closing

D. opening; closing

解析：考查情景交际。“谁没有关窗户？”“对不起，昨天我离开时忘记关了。”open可以作形容词，意为“开着的”，表示状态。forget to do sth.“忘记要做某事”；forget doing sth.“忘记做过某事”。本题意思是“没关”，故用forget to do。故选B。