单选题 At the meeting there was a hot argument and so many problems were left ______.
A. to solve B. solving C. solved D. unsolved

【正确答案】 D
【答案解析】[解析] 单词辨析题。会上讨论很激烈，很多问题都没有能解决。“没有解决”符合上下文的意思。