Great Leap Forward

big / broad, immense

to change; to become different; to turn into; to become (something else)

great strides, great progress, breakthrough

make great strides, make remarkable progress

the Great Leap Forward

economics; the study of economics / economy

age, era, period (of time) / the times, spirit of the age / antiquity / a time in one's life, one's days (in college etc.)

big; great

(historical or contemporary) any of several kingdoms, empires, or states of the Chinese people