color-changing period

drought period changing

Period changing

roll changing period

temperature changing period

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

Changing the Bones Theory

face-changing technique

2 GHz microwave frequency-changing

Abrupt changing characteristics

Ac freqnency-changing

adaptive rate changing