能帮解释下：he was all she spoke of these days.中all she spoke of是什么用法吗?

句子主干:He was all.这是一个"主系表"结构,all作表语,并做后面那个定语从句的先行词.
she spoke of these days .是省略了关系代词that的定语从句,修饰先行词all.
He was all (that) she spoke of these days.
句意:他是她这几天谈论的全部话题.非常感谢！还有一题：On sunday there were a lot of students playing in the park,__parents seated together joking.A.their B. Whose 选A.但这两个选项分不清。seated我知道是及物动词后面句子少主语，但是选Bwhose parents也可以作主语吧，好比My frends选A.their 是正确的. their parents seated together joking. 是独立主格结构做伴随状语. their parents 为seated的逻辑主语, seated不是谓动,而是过去分词作状语. 如用Whose引导定语从句,那么第二个分句必须为完整的句子:whose parents were seated together joking. 但seated不能单独作谓动,因此不能选B. Whose .