求高手帮我分析一下语法，不是在非限制性定语从句中，which 不能省的么，为什么circulated省了

Question

For example ,the Scottish Council for research in Education producted a package of materials, Action Against Bullying,circulated to all schools in England and Wales as well as in Scotland in summer 1992, with a second pack, supporting schools against bullying,produced the following year.
还有
circulated 对应的主语是谁啊？

Answer 1

译：
比如，苏格兰教育研究委员会制作了（produced？）一个材料包，名为“反欺凌行动”，这个材料包在1992夏天被发到了英格兰、威尔士以及苏格兰的所有学校。第二年，第二个支持学校反对欺凌的材料包被发放到所有学校。

这里并不是非限制性定语从句而是分词：
a package of materials, 【circulated】 to all schools……= a package of materials, 【which was circulated】 to all schools……

a second pack, 【supporting】 schools against bullying, 【produced】 the following year = a second pack, 【which supported】 schools against bullying, 【which was produced】 the following year

大致亦即：现在分词=which+主动语态，过去分词=which+被动语态

circulated的逻辑主语是a package of materials，Action Against Bullying是a package of materials的同位语。本回答被提问者采纳