I have to turn off the light.为什么要加the~有时我这个分不清～不知道是加the 还是a

I have to turn off the light.为什么要加the~有时我这个分不清～不知道是加the 还是a 歌Don't turn off the light的第一句是I Don't have to...还是The light the last one to leave turn off the light 为什么这个句子 I forgot to turn the light off.什么意思? you've left the light on.Oh,so i have --and turn it off A I' You're left the light on.Oh,so i have .[ ]and turn it off!a: You've left the light on.Oh,so I have.___ and turn it off A. don't forget to turn off the light A.yes ,I will B.no ,I won _____you leave,Don't forget to turn off the light.是用before还是 关灯,turn off the light,turn the light off对吗? Turn Off The Light 歌词 Please turn off the light