【简答题】The use of vacuum tubes declined rapidly when a semiconductor device was invented that could perform many of the functions previously associated with vacuum tubes.
【简答题】Power Semiconductor Devices (PSD) are devices used as switches or rectifiers in power electronic circuits. What is the difference of PSD and low-power semiconductor device?
【简答题】某服装加工厂某月生产A、B、C三种产品共4 000件,为了保证产品质量,进行抽样检验,根据分层抽样的结果,企业统计员制作了如下的统计表格: 产品类别 A B C 产品数量(件) 2300 样本容量(件) 230 由于不小心,表格中A、C产品的有关数据已被污染看不清楚,统计员记得A产品的样本容量比C产品的样本容量多10,根据以上信息,可得C的产品数量是( )。