So that all the living things died out gradually .
A. serious polluted the lake is
B. serious polluted is the lake
C. seriously polluted the lake is
D. seriously polluted is the lake
网友回答
A. serious polluted the lake is
B. serious polluted is the lake
(答案→)C. seriously polluted the lake is
D. seriously polluted is the lake
解析：倒装句型 so +adj/ad+（被修饰词）+主语，谓语