题目内容：

It is possible that there is a definite relation between these paintings and the markings that sometimes accompany them.句子成份是
them指的是什么，谁伴随谁

优质解答

首先是 it is +adj+ that 的结构 是主语从句,it 是形式主语,真正的主语在that部分
主语部分,是一个there be 句型
paintings markings是先行词,that smetimes accompany them是修饰他们的定语从句