hydraulic main water main
main pole and main zero
main road main scheme station
ring main structure of main and auxiliary lines
distance-true fold (concentric fold)
head fold-Cephalic fold
(Main spare part processing) craft
1 000 kV main transformer
10CrMo910 main steam pipeline
1-Main Bearing-Pump End
1-Main Bearing-Seal End
220 kV main transformer
220 kV main transformer protection
Ⅱcross-section main girder
3 main lines of time-cost-innovation