预约成功
211. be on duty 值班， 值日， 在上班时
212. be in duty bound to (do) (=be required by one's job or esp. by conscience) 有义务(做)
213. be eager for 想得到， 盼望
214. by ear (=play music from memory without having seen it printed) 凭记忆，不看乐谱
215. have an ear for (=have keen recognition of sounds esp. in music and language)对……有鉴赏力
216. a word in one's ear 私房话， 秘密话
217. on earth 究竟， 到底， 全然
218. with ease ( = easily) 容易， 不费力
219. at (one's) ease ( = without worry or nervousness) 自在，不拘束
220. put sb. at his her ease (=free sb. from worry or nervousness)使某人感到无拘束
