题干
—Please remember ________ the lights when you leave.
—OK, I will.
A：turn off
B：to turn off
C：turning off
答案(点此获取答案解析）
B
—Please remember ________ the lights when you leave.
—OK, I will.
A：turn off
B：to turn off
C：turning off
的加速度竖直加速上升时,细绳对物体的拉力是