0 an extremely small piece of matter with a positive or negative electric charge, produced when a radioactive atom is broken down -- ß粒子(在原子放射性衰变中产生的一种粒子,带一个正电荷或负电荷)
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。