So difficult _______ that no one could ______ a good solution to it. [ ]

A. was the problem; come up with    

B. the problem was; come up with

C. the problem was; put up with      

D. was the problem; put up with

萎黄是（）

A.面黄枯槁无光

B.面黄而虚浮

C.面目一身俱黄

D.面色青紫

E.面色不华、眼眶发黑