英语完型填空为什么要这样填 麻烦英语帝解释下!特别是that she would spend hours (writing) them.这句

Michel is a young girl who works for the police (as)a handwriting expert (专家).
Michel是一个以笔迹鉴定专家的身份为police工作的年轻女孩,as这里指作为.
She has helped (catch) many criminals (罪犯) by using her special talents.
主动语态中多用help do.
When she was fourteen,Michel was already (so) interested in the differences in her friends’ (handwriting) that she would spend hours (writing) them.
so.that 固定句型,如此...以至于...
handwriting是和前文内容衔接,无语法内容.
writing,固定短语spend some time in doing.
After (finished) college she went to France for a (special) two-year class in handwriting at the School of Police Science
finished college 过去时态短语作前置时间状语.
special根据语义选择,无语法内容.
Michel says that it is (impossible) for people at hide their handwriting.She can discover (most) of what she needs to know simply (by) looking at the writing with her own eyes,(but) she also has machines
(that) help her make (out) different kinds of paper and ink.This knowledge is often (of) great help to the police.
impossible,根据语义和全文内容选择,无语法内容.加上固定局势：It's +adj.+for sb.to do.
most of大多数,短语.
by,通过...的方式.
that 定语从句中作关系代词.
make out分辨,辨认,短语
be of,短语.
Michel believes that handwriting is a good (sign) of what kind of person the (writer) is."I wouldn’t go out with a fellow (if) I didn’t like his handwriting." She says.But she (adds) she fell in love with her future husband,a young policeman (before) she studied his handwriting.It is later proved to be (all right),however.
sign,根据文章内容选择,无语法内容.
writer,根据上下句内容选择,无语法内容.
if条件状语从句引导词
add,有【补充】的意思
before,时间状语从句引导词
all right 对的,合适的.