So that all the living things are dying out gradually .A. serious polluted the lake is B.

问题补充：

So that all the living things are dying 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

答案：

A. serious polluted the lake is

B. serious polluted is the lake

C. seriously polluted the lake is

(答案→)D. seriously polluted is the lake

解析：考查so…that…的倒装句，把so+adj/adv置于句首，句子用部分倒装，be动词，助动词或情态动词放在主语前，句意是：这个湖污染如此严重以至于所有的生物逐渐的快要灭绝了。选D。