ZPW-2000R型无绝缘移频轨道电路自动闭塞,室内其他配线均采用()阻燃塑料软线。 ["A、23×0.15mm","B、23×0.55mm","C、46×0.15mm","D、46×0.55mm"]
七月诗歌在思想内容上有何特点?
WG-21A型无绝缘轨道电路自动闭塞(“N+1”系统)设备在电源电压()范围内应可靠工作。 ["A、直流22.5V~28.8V","B、交流22.5V~28.8V","C、直流24.5V~34.8V","D、交流24.5V~34.8V"]
WG-21A型无绝缘轨道电路自动闭塞(“N+1”系统),发送器空载输出时电源电流()。 ["A、0.2A~0.3A","B、0.2A~0.35A","C、0.3A~0.5A","D、0.2A~0.5A"]
艾青诗歌创作中最为突出的主体意象有那些?
储集层的非均质性分哪几类?