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
- forbidden [spectral] line
- forbidden spectral line
- forbidden state
- forbidden subgraph
- forbidden transition
- forbidden β transition
- forbid someone to enter stadiums for watching certain sports games
- forbid to enter the country
- forbid to leave the country
- forbs
- Forbush decrease
- Forbush effect
- Forcadel
- force
- force actuator
- force admittance
- force admittance, force mobility
- force analysis
- force and torque metrology
- force balance of pump rotors
- force-balance-type transducer
- force between dislocations
- force-carrier particles
- force clamp spectroscopy
- force-clamp spectroscopy