题干
—The light in the office is still on.
—Oh, I forgot _______.
A：turning it off
B：turn it off
C：to turn it off
D：having turned it off
答案(点此获取答案解析）
C
—The light in the office is still on.
—Oh, I forgot _______.
A：turning it off
B：turn it off
C：to turn it off
D：having turned it off
，另一份与足量Na2CO3溶液反应放出气体V2升；若同温同压下V1＞V2，则M可能是