269. (be) in existence存在 come into existence 出现

268. come into existence (=begin to exist)开始存在; come into use开始使用; come into effect开始运转; come into fashion开始时新; come into action开始行动; come into power开始执政; come into sight进入视野;come into blossom开花;

267. exert oneself to do sth. 努力,使劲

266. exert…on… 对…施加…

265. in excuse of 作为…的借口

264. exclusive of (=not taking into account; without) 不包括

263. exchange…for 以…交换

262. in excess of (=more than) 超过

261. with the exception of (=except, apart from) 除去…., 除…以外

260. (an) exception to …的例外