Two of them seem particularly resistant to the effects of PCBs.

其中的两种变异似乎具有特殊抵抗PCB的作用。

But PCBs are persistent chemicals, and their effects are felt even today.

但PCBs是惰性化工品，即便是今天，的影响依然存在。

And DDT and PCBs two of the most poisonous and long-lasting substances known continue to threaten aquatic wildlife.

滴滴涕和多氯联苯是已知的两种毒性和持久性最强的物质，继续威胁水中的野动物。

For this, engineers had another innovation: printed circuit boards, or PCBs.

为此，工程师进行了另一项创新：印刷电路板或 PCB。

PCBs do their damage by binding to a protein called the aryl hydrocarbon receptor, or AHR, thus stopping it working properly.

PCB的危害来源于合一种称为芳香烃受体（AHR）的蛋白质，从而停止该类蛋白的正常运转。

After having spilled PCBs and other pollutants into the river in the 1970s, many industries simply moved leaving the contaminated sites behind.

在上世纪70年代，多氯联苯和其他污染物排入河流后，许多行业搬离了这些受污染的地方。

So, these are ducts (ph) and PCBs, heavy metals like lead and arsenic that have been in the soil, in sediment at these sites for decades.

因此，这些是管道 (ph) 和多氯联苯，重金属如铅和砷，几十年来一直存在于这些地点的土壤和沉积物中。

By using PCBs and ICs together, one could achieve exactly the same functional circuit as that made from discrete components, but with far fewer individual components and tangled wires.

通过将 PCB 和 IC 一起使用，可以实现与分立元件完全相同的功能电路，但单个元件和缠绕的电线要少得多。