PCBs (polychlorinated biphenyls), in widespread use since the 1930’s, are a family of over 200 oily compounds used in lubricants, plastics, electrical insulation, pesticides, dishwashing liquids, and other products.
收回 你的? 话- 我?" " 你 迫使 我呀 ", 但 你 不行jw2019 jw2019