【题目】You are students in the No．168 Senior High School now, but you _______ in different junior high schools for three years．
A．studies B．have studied
C．studied D．were studying
在线课程【答案】C
【解析】
试题分析：根据语境for three years...说明事情是发生在过去不确定的时间段，所以选择C。句意：当前你在第168中学学校学习，但在过去的三年里你在不同的中学学习过。