12._________,lack of clean fresh water presents an even greater threat.
问题描述：
12._________,lack of clean fresh water presents an even greater threat.
A.As bad as the air can be B.The air can be as bad
C.Bad as the air can be D.As the air can be bad
选C，句子怎么翻译？
答
我觉得应该是C吧,好像是什么as引导状语从句,adj提前,比如young as he is.
本来空气就很糟糕,干净水源的短缺更是构成了一个严重威胁