请问应该怎么理解what remained of a bottle of medicine从句

这句话的关键是要先理解介词短语of a bottle of medicine起什么作用.显然它是修饰remained的.但是它是状语吗?状语是表示动作状态的,而这里of a bottle of medicine讲的不是动作状态,而是类似于所有格.也就是说,它好像是一个修饰名词的定语!其实它就是定语!那么难道remained是名词吗?对,这里remained叫名词性形容词,即形容词起名词的作用.这么一看,what后面跟的根本就不是什么从句,而是一个名词性形容词短语作carrying的宾语.what在这里是副词修饰remained,意思是有多少,相当于how much.
因为remained也可以是remain的过去时,所以很容易搞混.我给你举两个真正用形容词的例子,就清楚了：
he went off immediately to visit him,carrying with him in his pocket 【what left of a bottle of medicine】 formerly prescribed for an indisposition of Mrs.Carlyle's.
I carefully saved 【what little of the remaining food】.
我毫不怀疑即使英文老师也有可能把它误认为从句.

第一句【what remained of a bottle of medicine】这部分属同位语从句 整个说明解释pocket. 全句是说他立刻起身去见他，口袋里还装着一瓶以前就为Carlyle夫人开好的药。 for an indisposition 可以不用翻 省的同意反复。 同位语从句还比如 I have no idea what has happened to him. There ...