帮忙解释一下下面这句话中的“in" 最好是能够还原一下这个句子.

问题描述:

帮忙解释一下下面这句话中的“in" 最好是能够还原一下这个句子.
One theory,dreamt up in all the spare time enjoyed by the alphabetically disadvantaged,is that the rot sets in early.

那些字母表上列位不佳者利用所有闲暇尽情幻想出来的一种理论认为,情况从一开始就很糟.

One theory(主语),dreamt up in all the spare time(后置定语,修饰theory) enjoyed by the alphabetically disadvantaged(后置定语,修饰theory),is(系动词) that the rot sets in early(表语从句).
in all the spare time:在所有的闲暇时间里
set in:开始.我想问一下enjoyed by the alphabetically disadvantaged(后置定语,修饰theory),这个enjoyed不是来修饰空闲时间(spare time)吗,享受空闲时间吗?哎,写错了,复制了没改。是修饰spare time的,跟在它后面的嘛。