精馏
Spanning Tree Protocol calculates path cost based on which of these？（） ["interface bandwidth","interface delay","interface bandwidth and delay","hop count","bridge priority"]
按照等强匹配原则，下列适宜焊接Q235A钢板的有（） ["J422","J427","H08A+HJ431","H10Mn2+HJ431"]
饱和含量
《行细》规定：哈西动车所开往哈尔滨西站方向为上行方向，反之为下行方向。（）
回流比
