217. on earth 究竟, 到底, 全然　­

216. a word in one’s ear 私房话, 秘密话　­

215. have an ear for (=have keen recognition of sounds esp. in music and language)对..有鉴赏力　­

214. by ear (=play music from memory without having seen it printed) 凭记忆,不看乐谱　­

213. be eager for 想得到, 盼望　­

212. be in duty bound to (do) (=be required by one’s job or esp. by conscience) 有义务(做)　­

211. be on duty 值班, 值日, 在上班时　­

210. go on duty 上班　­

209. come off duty 下班　­

208. be due to 是由于　­