英语高手帮我看看我写的这个句子对不对

Question

1.The trend, a shift from using fixed phone to cell phone, may also help account for the phenomenon of increasing mobile-phone subscription in developing countries.
2.Rapid economic development has been typical of developing countries,not least China since late 1978 when reform and opening up policies were launched. Accordingly of these countries,a dramatic increase in people's income can be seen,thus resulting in surging sales volume of smartphone.

Answer 1

第一句中的 subscription 用复数 subscriptions 就好。
第二题建议：
Rapid economic development has been typical of developing countries, China being an example since late 1978 when reform and opening up policies were launched. Accordingly in those countries, a dramatic increase in people's income may have in part resulted in the surging sales volume of smartphones.

供参考。