summer nights we often go to sleep the window open.A. At; with B. On; withC. In; forD.

问题补充：

summer nights, we often go to sleep the window open.

A. At; with

B. On; with

C. In; for

D. At; on

答案：

A. At; with

(答案→)B. On; with

C. In; for

D. At; on

解析：summer nights是特指的某天晚上，故用介词on。固定短语with the window open表示开着窗户，表示伴随动作，故用B。