I admit that there are problems I don’t think that they can’t be solved.A. WhileB. WhenC.

问题补充：

I admit that there are problems, I don’t think that they can’t be solved.

A. While

B. When

C. As

D. For

答案：

(答案→)A. While

B. When

C. As

D. For

解析：句意，“尽管我承认问题的存在，但我认为他们能够解决它”。While在此为连词，表示语气的转折，意思是“尽管、然而、但是”，故选A。