单选题 By next summer he ______ in the biology school of Harvard University for three years.
   A) will have been studying             B) will study
   C) have studied                      D) will be studying
【正确答案】 A
【答案解析】根据判断，我们可知句意：到明年夏季为止，他在哈佛大学生物学院求学已满三载。因为他现在仍在哈佛求学，所以应用将来完成进行时。