短语词组短语zero lift line 无升力线;零升力线zero grade line 施工基准线;路基施工准则线zero reactance line 零电抗线zero mean line 零均线zero stress line 零应力线zero accumulative line 零点收敛指数zero base line 零基线zero layer line 零层线;中层线Zero wind line 零风线 返回 zero line