206. without doubt (=undoubtedly)无可置疑地
　　207. in doubt(=in a condition of uncertainty)对…表示疑惑
　　208. be due to 是由于
　　209. come off duty 下班
　　210. go on duty 上班
　　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
　　221. economize on (=save sth. instead of being wasteful) 节省
　　222. have an effect on 对…有影响
　　223. be in effect (=be in operation) 有效
　　224. go into effect 生效. ( 近: come into effect; take effect; be brought into effect)
　　225. in effect (=in fact, really) 实际上
　　226. give effect to (=carry out) 实行,使…生效
　　227. to no effect 不起作用,没有取得任何效果
　　228. (be) of no effect (=useless) 无效
　　229. to the effect that 大意是…,主要内容是…
　　230. to that effect 是那个意思的…
　　231. emerge from ( =appear, become known ) 出现, 暴露(问题. 意见等)
　　232. place(or put, lay) an emphasis on 强调, 把重点放在…上
　　233. encourage sb. in 鼓励; encourage sb. in his/her work 鼓励某人工作; encourage sb. in his/her idleness 怂恿某人游手好闲
　　234. encourage sb. in …with sth. 用…鼓励某人做某事
　　235. on end (=continuously) 连续地
　　236. (be) at an end (=finished) 结束了
　　237. no end of (=very many/much) 很多,大量
　　238. in the end (=finally, eventually) 最终
　　239. at one’s wit’s end (=not knowing what to do or to say) 无法可想, 智穷计尽
　　240. end up with 以…而结束
　　241. come to and end (=finish) 结束
　　242. end in 以…为结束
　　243. engage in 或 be engaged in 忙于,从事