it's been found in laboratory testing that some types of oils are really bad for us.的句子结构

问题描述:

it's been found in laboratory testing that some types of oils are really bad for us.的句子结构

主语从句,句子主干为:it's been found that oils are bad.即:研究发现有些油对人们有害.
That后面是句子的实际主语,可以看出主语很长,从而用这种后置的结构是避免句子头重脚轻.
其他都是句子的次要成分.in laboratory testing意为“在实验室测验中”.