单词	mass center--center of mass
释义	center of mass; mass center质量中心
随便看	database access technique database administration database administration language data base administrator database administrator database administrator aid database administrator (dba) database administrator {=dba} database administrator--dba database administrator数据库管理员 database administrator，dba database analysis database analyst database and transaction management system database architecture database area file database audit database authorization file database automatic table look-up database availability database availability ratio database backup database backup dump database backup dump tape database backup series