It's dangerous ______with candles.A.to play B.playing C.plays D.for playing

A

A 对的啦

to play with candles 做形式主语

B playing
玩蜡烛是危险的。

动名词一般可用来表示日常进行的行为，动词不定式表示特定情况下进行的行为。

比如：
It's dangerous to play with candles when your parents are not with you.