89.简答发车站收到回执信号后为何发车表示灯不亮？
["\u7b54\uff1a\u8fd9\u7c7b\u6545\u969c\u57fa\u672c\u4e0a\u53d1\u751f\u5728\u53d1\u8f66\u7ad9\uff1a1\uff09\u5ba4\u5916\u8f68\u9053\u7535\u8def\u77ed\u8def\u30022\uff09\u51c6\u5907\u5f00\u901a\u7ee7\u7535\u5668ZKJ\u7535\u8def\u6545\u969c\u30023\uff09 \u5ba4\u5185\u8f68\u9053\u7ee7\u7535\u5668GDJ\u7535\u8def\u6545\u969c\u30024\uff09\u53d1\u8f66\u8868\u793a\u706fFBD\u7535\u8def\u6545\u969c\u30025\uff09\u706f\u6ce1\u63a5\u89e6\u4e0d\u826f\u6216\u65ad\u4e1d\u3002"]