第一百是hundredth还是onehundredth

是one hundredth，例如

Next week is the one hundredth anniversary of the Paris Air Show， the biggest in the world.下周是巴黎航空航展100周年纪念日，目前世界上规模最大的航展。

Well， sir， I hope to have the privilege of interviewing you on your one hundredth birthday.

先生，我希望我能荣幸地在您一百岁大寿时再来采访您。