Water is changed into steam by heat.这句话是被动句吗?

问题描述:

Water is changed into steam by heat.这句话是被动句吗?
Ice changes into water rapidly on a hot day.像这样子,明明可以是change作谓语.
为什么,这里是is作谓语?

其实change作及物(一般有by出现)和不及物动词都可以的Water is changed into steam by heat.在这里做及物,本来说Water changed into steam 也可以表达好意思的,无奈后面有个by heatIce changes into water rapidly o...