其实是动词现在分词,而不是动名词.
Silver is the best of electricity,copper following it closely
因为此句的谓语动词是is.而 copper following it closely是动词现在分词短语.
我明白你的困惑.其实我把上述句子拆成2个句子的话如下.
Silver is the best of electricity.Copper follows it closely.
这时就可用follows.
问题是原句是一个句子,所以后面follow就用动词现在分词短语,做非谓语动词.