Our country a lot in the last fifty years. A. will changeB. changedC. changesD. has chang

问题补充：

Our country a lot in the last fifty years.

A. will change

B. changed

C. changes

D. has changed

答案：

A. will change

B. changed

C. changes

(答案→)D. has changed

解析：句意是：我们国家在过去的五十年发生了许多变化。结合语境及时间状语in the last fifty years可知描述的是一直持续到现在的动作，故用现在完成时态，故选D。