Which is the smallest fraction in $$\frac{2020}{2021}$$, $$\frac{2021}{2022}$$, $$\frac{2022}{2023}$$ and $$\frac{2023}{2024}$$? 
Overseas Competition->Knowledge Point->Calculation Modules->Comparing, Ordering and Estimating
Sugar water theory. 1 gram of sugar added each time, and the sugar water gets sweeter. 