null ①零，零的 ②无效的，无价值的 ③类光[的]†
null 零的；零
数据库 数据库管理系统及其实现技术 释文 null 空值
- landscape evolution
- landscape factor
- Landscape Feeling
- landscape,Flower,Bird by Yun Shouping
- landscape fragmentation
- landscape fragmentation degree
- landscape function
- landscape gardening management
- landscape genetics
- landscape graphic methodology
- landscape heterogeneity
- landscape history
- Landscape in the Mist
- landscape lacunarity index
- landscape lighting
- landscape lighting in karst cave
- landscape maintenance machinery
- landscape map
- landscape mapping
- landscape metrics
- landscape mode
- landscape model
- Landscape Model of discourse comprehension
- landscape morphology
- landscape mosaic