什么是第一、第二、第三、第四的英文缩写？

The first, second, third, and fourth English abbreviations are AICP, CIAO, CPC, and PSC.

1 one first 2 two second 3 three third 4 four forth 5 five fifth 6 six sixth 7 seven seventh 8 eight eighth 9 nine ninth 10 ten tenth 11 eleven eleventh 12 twelve twelveth

13 thirteen 14 fourteen 15 fifteen 16 sixteen 17 seventeenth 18 eighth 19 nineteenth 20 twentieth 21 twenty-first 22 twenty-second 23 twenty-third 24 twenty-fourth 25 twenty-fifth 26 twenty-sixth 27 twenty-seventeenth 28 eighteenth 29 twenty-ninth 30 thirtieth