retrace
[ri'treis; ri:-; 'ri:treis]
vt.
折回；返回：
They retraced their steps to where they started.
他们顺原路又折回到他们出发的地点。
沿…重走；[比喻]走回头路，走老路：
We should not retrace the route our forefathers had taken.
我们不应重走我们祖先走过的老路。
追溯；探查：
You may encounter the same question whe