◎ 题干
____several times,but unfortunately,the boy still couldn’t smooth away the problem on his own.
A.Having been explainedB.The problem having been explained
C.The problem had been explainedD.Although the problem had been explained
◎ 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“____several times,but unfortunately,the boy still couldn’t smooth away the problem on his own.A.Having been explainedB.The problem having been explainedC.The…”主要考查了你对  【现在分词的被动式】【现在分词】【不定式的被动式】【过去分词】  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。