练习步骤：
step1：划分句子结构，找句子主干
step2: 确定修饰词，修饰短语或修饰从句的修饰关系
step3: 确定代词指代对象
剑桥雅思9
Reading Passage 1
长难句：Incorporating potassium dichromate and alcohol into the aniline at various stages of the experimental process, he finally produced a deep purple solution.
step1：划分句子结构，找句子主干
step2: 确定修饰词，修饰短语或修饰从句的修饰关系
step3: 确定代词指代对象
剑桥雅思9
Reading Passage 1
长难句：Incorporating potassium dichromate and alcohol into the aniline at various stages of the experimental process, he finally produced a deep purple solution.
