i just don't know off the top of my head.怎么翻译?不理解off 这个介词

i just don't know off the top of my head.怎么翻译?不理解off 这个介词 this is just off the top of my head now not off the top of my head Off the top of my head. off the top of my I don’t know how long it’ll be 　　　 I get the bandage off my Joe readily understands this--off the top of his head I just can't wrap my head around this.这个怎么翻译,wrap one's head If I let go of my hair, my head will fall off. 翻译一下 let us head off for the city 请问 off是介词怎么后边还有介词 Don`t turn off the lights.I need to know if what I am doing I don't know at which stop to let him off翻译中文意思