下列有关金属风管的制作与连接正确的是（）。 ["风管连接时，其螺栓孔的间距不得大于150mm","矩形风管法兰四角处应设有螺孔","板材不应采用咬口连接或铆接","镀锌钢板及含有复合保护层的钢板可采用焊接","风管应以板材连接的密封为主，密封面宜设在风管的正压侧"]
冰川侵蚀作用？侵蚀地貌类型？
Which command should you use to verify what networks are being routed by a given OSPF process（） ["show ip ospf","show ip route","show ip protocol","show ip ospfdatabase","None of the other alternatives apply"]
配电变压器供电电压高，可将变压器分接头（）。 ["解除","调低","调高","调至任意档"]
声调
结晶及重结晶作用
