0 a common metal, such as lead, tin, or copper, that reacts easily with other chemicals and is not a precious metal -- 賤金屬(如鉛、錫、銅)
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。