随着取代氯原子数的增加，同族体的含量逐渐降低。

With the chlorine increased from 4 to 7, PCBs homologue concentrations decreased in all the four samples.

youdao

随着取代氯原子数的增加，同族体的含量逐渐降低。

With the chlorine increased from 4 to 7, PCBs homologue concentrations decreased in all the four samples.

youdao