0 to give something you own as part of your payment for something you buy, especially a new type of the same thing -- 以…折價換購（尤指同類的新品）
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。
