0 used to express surprise or confusion, to ask someone to repeat what they have said, or as a way of getting someone to give some type of reaction to a statement that you have made -- (表示惊奇或不解,或者请对方重复或作出反应)啊,嗯,什么,是吗,好吗
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
再长的路,一步步也能走完,再短的路,不迈开双脚也无法到达。