[单选题]下列()是错误判断高铁牵引变电所馈线过负荷跳闸条件的? A.电压20kV以上或合成电压40kV以上 B. T、F合成电流值在馈线过流保护定值左右(过流保护动作时电流不小于保护整定值,阻抗保护动作时电流一般在过流保护整定值±100A左右) C. T-R故障,供电臂内有动车组运行 D. 阻抗角在55度以上
[听力原文]
W: Thank you very much for such a splendid dinner.
M: I’m glad you enjoy it.
When does the conversation probably take place() A. Before the meal. B. During the meal. C. When the guest arrives. D. When the guest leaves. 参考答案:D 答案解析: