6、ound(find的过去式,过去分词)找回v.37.lost and found失物招领38.please(祈使句用作请求的客套话)请interj39.school学校n.40.a set一套;一副41.of(属于)…的42.excuse原谅;宽恕v.43.excuseme请原谅第三单元单词及短语1.sister姐;妹n.2.mother妈妈;母亲n.3.father爸爸;父亲n.4.parent父亲或母亲n.5.brother兄;弟n.6.grandmother祖母;外祖母n.7.grandfather祖父;外祖父n.8.friend