基本解释头部前体同根派生 英汉例句19Is there a process to prehead PCB before potting black poly? 19 是否有密封黑色多晶硅之前预热印刷电路板的流程?19 Is there a process to prehead PCB before potting black poly? 在融化黑塑之前是否有预热PCB的处理？scaffolded prehead 有支架的前头部