Write these numbers in words 这些什么th rd 的是什么东东?

① 英语序数词表顺序,基数词表总数.th、st、nd、rd是由基数词变为序数词时需加的词尾,当然,要因词而异!其中,st用于指代first；nd指代second；rd指代third.例如：
one－－first two－－second three－－third
four－－fourth five－－fifth six－－sixth
seven－－seventh eight－－eighth nine－－ninth
ten－－tenth eleven－－eleventh twelve－－twelfth
twenty－one －－ twenty-first
twenty-two －－ twenty-second
twenty－three －－ twenty-third
② 1.73rd seventy-third
2.31st thirty-first
3.42nd fourty-second
4.18th eighteenth
5.100th one hundredth