◎ 题干
It remains _______ whether the medicine will work on human body.

[     ]

A. seen
B. to seen
C. seeing
D. to be seen
◎ 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“It remains _______ whether the medicine will work on human body. [ ]A. seen B. to seen C. seeing D. to be seen …”主要考查了你对  【不定式的被动式】  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。