. He made up his mind to devote his lifethe riverpolluted.A. to prevent to beB. to preven

问题补充：

. He made up his mind to devote his lifethe riverpolluted.

A. to prevent, to be

B. to prevent, from being

C. to preventing, to be

D. to preventing, from being

答案：

A. to prevent, to be

B. to prevent, from being

C. to preventing, to be

(答案→)D. to preventing, from being

解析：考查devote和prevent的用法。Devoteto致力于……，把……专注于，To是介词，后面接名词或者动名词。Prevent……from，From为介词，后面接名词或者动名词。阻止，预防某人干某事。句意：他决定把他的医生致力于防止河流免于污染的事业中。故选D。