I beilieve Zoe will pass the exam,she ( ) for it for such a long time C 还是D 不懂啊
问题描述：
I beilieve Zoe will pass the exam,she ( ) for it for such a long time C 还是D 不懂啊
A is preparing B was preparing C had been preparing D has been preparing
答
选D 因为根据前句语境,是现在时,所以应该用现在完成时.