下列变化中，属于化学变化的是（） A．用石墨粉打开生锈的

下列变化中，属于化学变化的是（）

A．用石墨粉打开生锈的铁锁 B．金刚石加工成项链

C．石墨转化为金刚石 D．铅笔芯折断

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下列变化中，属于化学变化的是（ ） A．用石墨粉打开生锈的

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下列变化中，属于化学变化的是（） A．用石墨粉打开生锈的