道床的英文：
(of railroad transportation) ballast
n. 铁路；铁路公司
v. 迫使；捏造不实之罪使入狱；铺设铁路；在铁路工作；由铁道运输；乘火车旅行
- It is veined by railroads.
铁路线四通八达。 - They ballasted the railroad.
他们给铁路铺道渣。 - They paved the trunk line of a railroad.
他们铺设了铁路的干线。
n. 运输，运送；流放；运输工具
- To transport by boat.
用船运输 - transportation leakage
运输漏损量 - He was sentenced to transportation for life.
他被判处终身流放。
n. 压舱物，压载物；道渣，碎石
v. 给…装压舱物；给…铺道渣
- They ballasted the ship.
他们给船只装压舱物。 - They ballasted the railroad.
他们给铁路铺道渣。 - The ballast placed in the ship can keep the ship steady.
放在船上的压舱物可以保持船的平稳。