At times the balance in nature is resulting in a number of possibly unforeseen effects.A.

问题补充：

At times the balance in nature is ，resulting in a number of possibly unforeseen effects.

A. troubled

B. confused

C. disturbed

D. puzzled

答案：

A. troubled

B. confused

(答案→)C. disturbed

D. puzzled

解析：考查词义辨析。troubled 麻烦的，confused 困惑的，disturbed 扰乱的，puzzled 迷惑的，句意：有时候大自然的平衡是扰乱的，导致了许多可能未预见的影响。所以选C。