people who do manual work=>blue-collar workers

people who work in offices/do mental work=>white-collar workers

for more money

far-副词用来加强语气==much

refer to...as = regard...as 把...看作为

I always refer to him as boolworm(书呆子)

for the simple reason=>for 引导的原因状语从句

for the reason that比because正式，因此多用于正式文体

human nature人性

such...that...

that引导同位语从句，进一步补充说明such的基本内涵

His kindness was such that we will never forget him.

=》Such was his kindness...

Such is human nature that we want to get a lot of things free.