◎ 题干
Mary with her friendsusually _____ twice a week.   
[     ]
A. exercises  
B. exercise  
C. is exercising  
D. are exercising
◎ 答案
查看答案
◎ 解析
查看解析
◎ 知识点
    根据魔方格专家分析,试题“Mary with her friendsusually _____ twice a week. [ ]A. exercisesB. exerciseC. is exercisingD. are exercising …”主要考查了你对  【实义动词的单数第三人称形式】  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。