frequency and period measuring method
period measuring and protection equipment
Period Signal Measuring Instrument
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
11th Five Year Scheme Period
11th-Five-Year Plan Period
12th five-year plan period
Golden period of development
Left-wing Federation period
(+)Period of time interrupt
‘Tenth Five－Year Plan’period