symmetric key对称密钥symmetricadj.对称的；匀称的symmetric cryptography对称密码symmetric illumination对称照明symmetric nonlinearity对称的非线性symmetric distribution对称分布symmetric multiprocess[计] 对称多处理机symmetric output swing对称输出振幅symmetric biderivation对称双导symmetric top molecule对称陀螺分子symmetric inforrnation对称信息symmetric harmonic map调和映射