ZN28-10型真空开关应定期检查触头烧损程度，具体是检查动导电杆伸出导向板长度的变化情况，若总的变化量超出3mm，则应更换灭弧室。
参考答案：对
(b) Within the context of corporate governance, explain the role of non-executive directors of public companies in the South African company law. (6 marks)
大细胞性贫血主要见于哪种疾病
A．缺铁性贫血B．感染性贫血C．溶血性贫血D．巨幼红细胞性贫血E．再生障碍性贫血
