◎ 题干
I am sorry that I have kept you ______ me so long.  
[     ]
A. waiting
B. waiting for
C. to wait
D. to wait for
◎ 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“I am sorry that I have kept you ______ me so long.[ ]A. waitingB. waiting for C. to waitD. to wait for…”主要考查了你对  【动名词】【动词短语】  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。