分词

分词
原句：If we heat water enough,we can change it into vapour.
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1.Heating water enough,we canchange it into vapour.
2.If we heat it enough,water can be changed into vapour.
3.Heated enough,water can be changed into vapour.
为什么第三句开头要用过去分词（理由）,能不能和第一句一样用现在分词?
我的意思是第三句Heated enough为什么不能改成being heated enough？
Being heated enough,water can be changed into vapour.为什么？