再热裂纹
M―A组元
新《技规》普速铁路部分第189条、新《技规》高速铁路部分第168条动车组须配备机车综合无线通信设备（CIR）、列控车载设备、车载自动过电分相装置等，满足相应速度等级运行需要。（）
小铁研实验我们主要是用来测定钢材的冷裂纹倾向，其实验方法是两侧焊双y型拘束焊缝，试验焊缝为斜y型，需要检测三个地方裂纹率，这三个地方是（） ["表面裂纹率","根部裂纹率","断面裂纹率","焊趾裂纹率"]
Loop guard and UniDirectional Link Detection both protect against Layer 2 STP loops. In which two ways does loop guard differ from UDLD in loop detection and prevention？（） ["Loop guard can be used with root guard simultaneously on the same port on the same VLAN while UDLD cannot.","UDLD protects against STP failures caused by cabling problems that create one-way links.","Loop guard detects and protects against duplicate packets being received and transmitted on different ports.","UDLD protects against unidirectional cabling problems on copper and fiber media.","Loop guard protects against STP failures caused by problems that result in the loss of BPDUs from a designated switch port."]
教育组织形象
