tetrad 四元组，四分体
four combination 四元组 quad 四角形区域，四元组 quadruple 四元组；四重的，四倍的 quadruplet 四元组 quaternary 四进制的，四元的；四元组 tetrad 四元组 vierbein 四元组
系统软件 语言与编译 释文 quadruple 四元组
- Japan Magazine Publishers Association
- Japan Meteorological Agency
- Japan News Network
- Japan one village, one product
- Japan Patent Information Organization
- Japan Playwrights Association
- Japan Proton Accelerator Research Complex
- Japan Railway Disaster Prevention System
- Japan Railway Technical Research Institute
- Japan Satellite Broadcasting Inc
- Japan's bombardment of the Xinshenglong Ship
- Japan Science and Technology Agency
- Japanse army's experiments for biological weapons
- Japan's modern agricultural economy
- Japan Society for the Study of the Book of Songs
- Japan Society of Chinese Ci Poetry
- Japan Society of Human Culture
- Japan Society of Library and Information Science
- Japan Society of Publishing Studies
- Japan space activities
- Japan Standard Time
- Japan stemona
- Japan thistle
- Japan Trench
- Japan Tsukuba science city