as we were taught at school，在句中作非限制性定语，还是作状语？
如果是作非限制性定语从句，那么，关系代词as代表什么？
前后文，分别如下：
I have known very few writers, but those I have known, and whom I respect, confess at once that they have little idea where they are going when they first set pen to paper. They have a character, perhaps two; they are in that condition of eager discomfort which passes for inspiration; all admit radical changes of destination once the journey has begun; one, to my certain knowledge, spent nine months on a novel about Kashmir, then reset the whole thing in the Scottish Highlands.
I never heard of anyone making a ‘skeleton’, as we were taught at school.
In the breaking and remaking, in the timing, interweaving, beginning afresh, the writer comes to discern things in his material which were not consciously in his mind when he began.
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FROM 114.253.13.*