How far is it from your home to school？这个句型里的is it是什么用法？和后面的from部分是什么关系？

Question

如题所述

Answer 1

一、How far is it：特殊疑问词 how far 加一般疑问句。类似：what is it？
二、it在本句中指代距离，例如：it is 5 kilometres away from here to school.
三、from your home to school 地点状语

Answer 2

主语从句的问法。
it is 500 km far from your home to school.对500km提问就是这样了。