its economy ____ rapidly in the past ten years

问题描述:

its economy ____ rapidly in the past ten years
a: has been developing
b: has been developed
c: have been developing
d: have been developed
答案和详细原因
答案是A 为什么

现在完成进行时,表示从过去某一时间开始,一直延续到现在,并且还正在进行的动作.