it is about 2 kilometers long from here to our school

问题描述:

it is about 2 kilometers long from here to our school
it 指什么 如果是,那long可以用吧 the distance is about 2 kilometers.
就像 the ruler is 15 centimeters long.

long改成away,这里讲的是距离而不是长度,与 the ruler is 15 centimeters long这句不一样.