bù / tóng / cái / liào / de / zǔ / kàng / bù / tóng / huì / yǐng / xiǎng / xìn / hào / chuán / shū / de / zhì / liàng不同材料的阻抗不同,会影响信号传输的质量。Different materials have different impedance, which affects the quality of signal transmission.