10:first second third forth fifth sixth seventh eighth ninth tenth
后面10以上的都是按照1~10结尾
记住 1、2、3是first second third就可以 其他都是th.
如果简写的话是这样：1st 2nd 3rd 4th 5th...21st 22nd 23rd 24th 25th...
明白了吧?挺简单的