Carboniferous Period—Permian Period
Demand charge shift from the on-peak period to the off-peak period
middle_period and last_period state_mines
Paleogeng Period-Neogene Period
period shut-down (period trip)
period-to-period value changes
Spring and Autumn period and Warring States period
the Spring and Autumn Period and the Period of War
burn one‘s own way of retreat and be determined to fight to the end
cut off all means of retreat
glacial advance and retreat