30天用英语怎么说（30用英语怎么说）

1 one first 1st 2 two second 2nd 3 three third 3rd 4 four fourth 4th 5 five fifth 5th 6 six sixth 6th 7 seven seventh 7th 8 eight eighth 8th 9 nine ninth 9th 10 ten tenth 10th 11 eleven eleventh 11th 12 twelve twelfth 12th 13 thirteen thirteenth 13th 14 fourteen fourteenth 14th 15 fifteen fifteenth 15th 16 sixteen sixteenth 16th 17 seventeen seventeenth 17th 18 eighteen eighteenth 18yh 19 nineteen nineteenth 19th 20 twenty twentieth 20th 21 twenty-one twenty-first 21st （20往下都是有规律的。

规律是twenty+10以内序数词。

30 40 50 ……都是这样） 30 thirty thirtieth 30th。