0 the point in the orbit (= curved path) of the moon or a satellite when it it is closest to the earth -- (月亮或人造卫星的)近地点
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。