The mayor of Beijing says that all construction work for the Beijing Olympics ________ by 2008.
A.has been completedB.has completedC.will have been completedD.will have complete在线课程C
解析：
从题干的逻辑关系看，本题应该使用被动语态，故排除B、D两项；
由时间状语by 2008可知，应该使用将来完成时的被动语态，表示从将来某一时间看已经完成的动作。