secondary cut多次切割secondaryadj.次要的；从属的；中等教育的n.副手；次要位置secondary inoculation reaction继发性接种反应secondary wastewater treatment污水二级处理secondary pump variable volume二次泵变流量secondary disease of dysentery痢后风secondary motor correspondence继发性运动对应secondary natural radionuclide次级天然放射性核种Secondary cooling water system二次冷却水系统secondary tuberculosis of lung继发性肺结核secondary geological disasters次生地质灾害Secondary nasolabial deformity鼻唇继发畸形

1. In nonwoody plants the primary xylem is the only water-conducting tissue, but in mature plants with secondary growth this function is mostly taken over by the secondary xylem.
   在尚未木质化的植物中，初生木质部是唯一的输水组织，但在具有次生生长的成熟植物中，该功能大多由次生木质部行使。