◎ 题干
When Jack arrived, he learned Mary _____.
[     ]
A. has left
B. is leaving
C. had left
D. left
◎ 答案
查看答案
◎ 解析
查看解析
◎ 知识点
    根据n多题专家分析,试题“When Jack arrived, he learned Mary _____. [ ]A. has left B. is leaving C. had left D. left…”主要考查了你对  【过去完成时】  等知识点的理解和应用能力。关于这些知识点的“档案”,你可以点击相应的链接进行查看和学习。