大家帮我看看这几个英语句子，顺便给我分析一下句子结构，谢谢了

Question

1.What was the difference between Bruce's behaviour and that of other people? that of 这个怎么解释？
2. He went into a low gear and drove at a terrifying speed,keeping the front wheels astride the carck as he followed its zigzag course.
这里的as作何解释？从语法的角度看他在这里起到什么作用？course该翻译成什么意思？
3.Rarely have the fortunes of technology companies appeared to differ so widely.
这个句子主语在那儿啊？怎么解释？

Answer 1

1、that用为抽象名次的指示代词，在这里只带抽象意义的“行为（behaviour）”，that of others就是别人的行为

2、as是when的意思，course是路径的意思，就是“当他驶入急转弯时”

3、这句话是倒装句，主语是the fortunes，正序为：the fortunes of technology companies rarely have appeared to differ so widely.意思是“科技公司的财富似乎很少有如此差异。”本回答被提问者采纳

Answer 2

1. that of - 用来代替behaviour，使其不必进行重复。
2. as-并且，与此同时； 起到并列的作用；course - 路线的意思。
3. 主语是companies; 翻译成：极少拥有技术财富，公司们显示出极大差别。

Answer 3

that 是代词 指代的是行为 也就是 the behavior of other people =that of other people 避免重复就用that代替behavior
as 随着，当。。时，和
when 的意思差不多 course 是路线的意思
句首的rarely是否定的意思 这样的词放在句首句子要倒装， the fortunes of technology companies (主语）have Rarely appeared (联系动词 和be动词功能一样）to differ so widely.(表语）