However，at times this balance in nature is _______ resulting in a number of poss

题干

However，at times this balance in nature is _______ resulting in a number of possibly unforeseen effects.

A．troubled

B．disturbed

C．confused

D．puzzled

上一题下一题 0.85难度单项选择更新时间:2011-11-14 09:51:02

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