1)principal series,主线系2)main piping,主干线管系3)Main-thread of Serial Courses,系列课程主线4)bus arrangements,电气主接线系统5)main system connecting diagram,系统主接线图6)master antenna distribution systems,主天线分配系统
用法例句
With this method,the principal series of 4 p-15 p energy levels of Na atom were calculated.