Mr.White has warned his son to be careful __ the danger,but his son didn't listen to him.

问题描述:

Mr.White has warned his son to be careful __ the danger,but his son didn't listen to him.
a.of b.on c.with d.for
这个选啥啊?还有为什么啊~

of.
to be careful of sth是固定短语--当心,注意的意思
句子的意思:怀特先生警告他的儿子要注意危险,可他儿子不听.