英语语法问题（长难句）the greatest improvements in the productive power

whihc修饰它前面的skill,dexterity and judgement,it 应该是指labor,就是最开始一个分句中"the productive powers of labour"里的那个,with which这个从句改成正常的语序就是it is directed or applied with something,这个something就是它前面紧接的skill,dexterity and judgement,即“用技巧、灵活性与判断能力来指导或实施劳动”.
have been 句型：首先是已经结束的过程,所以是完成时；然后,因为主语是由and 连接的两个部分,所以是复数.
这个句子的翻译可以这样：
劳动的生产能力中最大的进步,以及用于指导或实施劳动的技巧、灵活性和判断能力,看来都是劳动分工的成果.

the greatest improvements in the productive powers of labour, and the greater part of the skill, dexterity, and judgement, with which it is anywhere directed, or applied, seem to have been the effects...

which修饰的应该是skill，dexterity和judgement，with which引导的是定语从句，但是在这个从句里面是状语的成分。seem 的主语是the greatest improvements 和 the greater part,用have been 是表示对劳动力的分配已经形成了影响。至于it指代啥，咱也弄不明白，会不会和上下文联系起来读读会比较好懂？...

which 指的是the greater part of the skill, dexterity, and judgement,
it指the greatest improvements
因为主语是the greatest improvements 后面不能用主动语态 只能用have been句型而为什么不用 be become 是因为语境所决定的，with which i...