2023
The column chart on mobile-phone subscriptions above shows a striking contrast between those developing countries and developed countries in the past decade. Since 2023, people in growing numbers in developing countries use mobile phone, while those in developed countries far lag behind. By 2023, there are 4 billion mobile-phone users in developing countries, which is 3 times more than that in developed countries.
　　Two reasons may contribute to the contrast above. On the one hand, with the ...