题目

图为X射线管的结构示意图，E为灯丝电源，要使射线管发出X射线，须在K、A两电极加上几万伏的直流高压。            （   ）       A．高压电源正极应接在P点，X射线从K极发出       B．高压电源正极应接在P点，X射线从A极发出      C．高压电源正极应接在Q点，X射线从K极发出       D．高压电源正极应接在Q点，X射线从A极发出 The wealthy merchant went into the house, with two bodyguards ____ him.  A. to follow  B. following  C. follow  D. followed