He made up his mind to devote his life____________the river____________polluted
A.to prevent, to be
B.to prevent, from being
C.to preventing, to be
D.to preventing, from being
网友回答
D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。