【题目】—Have all the mysteries been cleared up?
— Almost. But ______ only one question ______.
A. there remains; answered
B. it remains; to be answered
C. there remains; to be answered
D. it remains; answered
在线课程【答案】C
【解析】
试题分析：考查there be句型及不定式作定语。句意：——所有的谜团都解开了吗？——几乎都解开了。只剩下一个还未解决。