drift value

例句：

1. 1. The boat drifted aimlessly in the river.
   这艘船在河里漫无目的地飘荡。
2. 2. The ship drifted away from the dock.
   船从码头上漂走了。
3. 3. The car drifted off the road and hit a tree.
   汽车偏离了道路，撞上了一棵树。