英语中的第几第几除了第一用the first,第二用the second ,第三用 the third, 第四用the forth, 第五用 the fifth 外,基本上都是在数字后加th
比如第一周至第十周
the first week
the second week
the third week
the forth week
the fifth week
the sixth week
the seventh week
the eighth week
the ninth week
the tenth week
第十一开始已经全部在数字后加"th"就可以了。
the first week第一周
the second week第二周
the third week
the forth week
...