0 to start to have an effect or to happen -- 开始见效;起作用
It takes half an hour for the medication to kick in. 药片半小时后药力开始显现。
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。