0 a small piece of metal or plastic used to fasten clothes with two usually round parts, one of which is pushed into the other -- 摁扣,子母扣
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。