英语专八词汇词组复习 be on duty 值班, 值日, 在上班时be in duty bound to (do) (=be required by ones job or esp by conscience)有义务(做)be eager for 想得到, 盼望by ear (=play music from memory without having seen it printed) 凭记忆,不看乐谱have an ear for (=have keen recognition of soun
