你好。是
定语从句的一部分。给你一个例句吧:
Very much do we appreciate your help,without which we would still have been doing our hard work.today .----------- We very much appreciate your help. Without your help, we would still have been doing our hard work today ----------这里的which就是your help, without-----解释为“没有"------也就是:没有你的帮助。本回答被提问者采纳