Over millions of years, this river shaped the valley.
Tips
usage
千百万 stacks 千 (thousand), 百 (hundred), and 万 (ten thousand) to mean 'countless multitudes,' parallel to the English 'millions upon millions.' It is a rhetorical intensifier rather than a precise number, common in political speeches and historical writing referring to 'the masses' (千百万人民群众).
memory
Read it as a stack of magnitudes: 千 (1,000) + 百 (100) + 万 (10,000) - far too many to count, so it just means 'multitudes.'
