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
答
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”.