The causes of tarnishing gold and silver - plated connectors were studied respectively.分别探讨了接插件镀金和镀银层变色的原因.Bright tin electrodeposits on copper wire are susceptible to tarnishing.铜线材经光亮镀锡后易产生腐蚀变色.Do they not realize thei...
There were low, muffled voices rising from the hallway.从走廊里隐约传来了低沉的说话声。I heard the voices, but couldn't make out what they were saying.我听到有声音，却听不清他们在说些什么。There was a sound of loud voices from the kitchen.厨房传来一阵喧闹声。...