第1 first 1st(简写)第2 second 2nd第3 third 3rd第4 fourth 4th第5 fifth 5th第6 sixth 6th第7 seventh 7th第8 eighth 8th第9 ninth 9th第10 tenth 10th第11 eleventh 11th第12 twelfth 12th第13 thirteenth 13th第14 fourteenth 14th第15 fifteenth 15th第16 sixteenth 16th第17 seventeenth 17th第18 eighteenth 18th第19 nineteenth 19th第20 twentieth 20th第21 twenty-first 21st第22 twenty-second 22nd第23 twenty-third 23rd第24 twenty-fourth 24th第25 twenty-fifth 25th第26 twenty-sixth 26th第27 twenty-seventh 27th第28 twenty-eighth 28th第29 twenty-ninth 29th第30 thirtieth 30th第31 thirty-first 31st第32 thirty-second 32nd第33 thirty-third 33rd第34 thirty-fourth 34th第35 thirty-fifth 35th第36 thirty-sixth 36th第37 thirty-seventh 37th第38 thirty-eighth 38th第39 thirty-ninth 39th第40 fortieth 40th第41 forty-first 41st第42 forty-second 42nd第43 forty-third 43rd第44 forty-fourth 44th第45 forty-fifth 45th第46 forty-sixth 46th第47 forty-seventh 47th第48 forty-eighth 48th第49 forty-ninth 49th第50 fiftieth 50th