To produce one pound of honey , a colonyof bees must fly a distance equal to twice around the world.
某资料中说上面这个句子是定语从句
To produce one pound of honey , a colonyof bees must fly a distance (that is) equal to twice around the world.
省略了"that is"后的样子。
但我觉得这个是属于形容词短语equal to作定语后置。资料和我的解释哪个是正确的呢?