bottomsn.底；末尾；臀部名词bottom的复数形式.bottomn.底部；底端adj.底部的v.触底；打(基础)bottomvalve[化] 底阀bottom bunk下铺bottom zone底区bottom head底盘bottom time水下工作时间bottom tool底锻模bottom view底视图,仰视图bottom coke底焦bottom bell底料钟bottom plow铧式犁