https://zh.paraquee.com/post/the-figure-below-shows-the-division-of-the-world-after-the-multi-peak-distribution-curve-is-formed-according-to-the-level-of-economic-production-and-income-indicators-of-each-country-according-to-the-concept-of-the-world-system-which-of-the-following-explanations-is-correct