在非限制性定语从句中，关系代词as和which都可指代整个主句或主句的一部分，并对其加以补充或说明，但两者在用法上存在着以下几方面的区别：1．在指代整个主句时，as引导的从句可位于主句句首、句中或句后，而Which引导的从句只能位于主句之后，如：Ashelateradmitted,itwasa In the non-restrictive attributive clauses, the relative pronouns as and which can refer to the entire main sentence or part of the main sentence, and supplement or explain it, but there are differences in the following aspects in terms of usage: 1. When referring to the entire main sentence, the guided clause of as may be located at the beginning of the main sentence, in the sentence, or after the sentence, while the clause guided by the whisker can only be located after the main sentence, such as: Asherateradmitted, itwasa