这是什么句式（的意思是）

1、Such sentences do not always occur in thinking,and when they do they are merged with vague imagery and the hint of unconscious or subliminal activities going on just out of range.2、 Thinking, as it happens, is more like struggling, striving, or searching for something than it is like talking or reading. Words do play their part but they are rarely the only feature of thought.

“and when they do they”,as it happens这是什么句式？的意思是？going on just out of range的意思是？是短语吗？do play their part的意思是？rarely，only 在该句中的意思是？

1 你断句错误，and when they do为时间状语从句，they是主句的主语。do为助动词替代，替代前面occur in thinking.

2 as it happens在此为时间状语从句，it指代thinking，当思维发生时，

3 going on just out of range. 在思维范围以外进行着。为with复合结构中的宾补。

4 rarely为半否定词，几乎不。only：唯一的，仅有些。

网友的英语水平不足以阅读此类文章，这会打击你学习英语的积极性。建议你换一个很容易的题材。