Before revision:  In our empirical study, we find that European countries overall flatten the curves more effectively compared to the other regions, while Asia & Oceania also achieve some success, but the situations are not as optimistic as in Europe . Africa and America are still facing serious challenges in terms of managing the spread of the virus  and reducing the death rate . In Africa, the rate of the spread of the virus is slower and the death rate is also lower than those of the other regions.
After revision:  In our empirical study, we find that European countries overall flatten the curves more effectively compared to the other regions, while Asia & Oceania also achieve some success, but the situations are not as optimistic as in Europe . Africa and America are still facing serious challenges in terms of managing the spread of the virus and reducing the death rate , although in Africa the virus spreads slower and has a lower death rate than the rate of the spread of the virus is slower and the death rate is also lower than those of the other regions.