I admit that there are problems I dont agree that they cannot be solved.A. WhileB. IfC.

问题补充：

I admit that there are problems, I don agree that they cannot be solved.

A. While

B. If

C. In case

D. Before

答案：

(答案→)A. While

B. If

C. In case

D. Before

解析：while表“虽然”，引导让步状语从句。