We are sure everything here by the time you come back from abroad in a few years.A. had c

问题补充：

We are sure everything here by the time you come back from abroad in a few years.

A. had changed

B. will have changed

C. had been changed

D. will have been changed

答案：

A. had changed

B. will have changed

C. had been changed

(答案→)D. will have been changed

解析：考查时态。句意：我们相信这的一切事情，在你几年后从国外回来时能够全部改变。结合语境可知从句描述的是将来某个时刻完成的动作，用将来完成时态，everything是被改变的对象，故用被动语态，选D。