【摘要】大学英语四级词汇高频词汇8 211. be on duty 值班, 值日, 在上班时 212. be in duty bound to 有义务 213. be eager for 想得到, 希望 214. by ear 凭记忆,不看乐谱 215. have an ear for 对..有鉴赏力 216. a word in ones ear 私房话, 隐秘话 217. on earth 毕竟, 究竟, 全然 218. with ease 简单, 不费劲 219. at ease 拘束,不拘束 220. put sb. at his her ease 使某人感到无拘束 221. economize on 节约 222. have an effect on 对有影响