eight/eighteen/eighth/eighty

eight /eit/ I. num. 八：the eight of them 他们八个人；the eight-hour day 八小时工作制 ‖II. n.八(岁，时，个等)：a child of eight 八岁的孩子 He came at eight. 他是八点来的。Two eights make sixteen. 二八一十六。

eighteen /ˈeiˈti:n/ num. & n. 十八(岁，个，人，时等): in the eighteen fifties 十九世纪五十年代She is eighteen. 她十八岁。

eighth /eitθ/ num. 1. 第八：in the eighth century在八世纪；the eighth of September 9月8日；the Eighth Route Army 八路军 She finished eighth of the eleven runners. 在11名赛跑选手中她获得第8名。2. 八分之一：an eighth of an inch 1/8英寸

eighty /ˈeiti/ I. num.八十：Twelve and eighty is ninety-two. 十二加八十等于九十二。 ‖II. n. (pl)1.八十年代： This happened in the eighties.这事发生在八十年代。 2.八十至八十九岁的时期：He is well in his eighties. 他八十好几了。