地图: map...
以后: after, later, afterwards, following, later on, in the future...
费劲: to require effort, strenuous...
研究: research, a study, to research, to look into...
水管: water pipe...
统治: to rule (a country), to govern, rule, regime...
医生: doctor...
更换: to replace (a worn-out tire etc), to change (one's address etc)...
空隙: crack, gap between two objects, gap in time between two events...
推算: to calculate, to reckon, to extrapolate (in calculation)...
