China is developing of all the countries in the world.A. fastB. fasterC. fastestD. the mo

问题补充：

China is developing of all the countries in the world.

A. fast

B. faster

C. fastest

D. the most fast

答案：

A. fast

B. faster

(答案→)C. fastest

D. the most fast

解析：根据后文的all ，可知答案为C，表示最高级。