1, one-first abbreviation1st; ;

2, two seconds abbreviation 2nd；;

3. One-third abbreviation 3rd；;

4.four-fouth is abbreviated as 4th；;

5.fifth-fifth is abbreviated as 5.

Extended data:

Ordinal number and abbreviation:

6-10: No.6 No.6; Seventh session; Eighth and eighth; The ninth session; No. 10 10.

1 1-20:No. 1 1 eventh 1 1; No 12 twelfth 12; Issue 13, issue 13, issue 13; Issue 14, issue 14, issue 14; No. 15 No.5 15; No. 16 Hexa 16; No. 17 sevententh 17; No. 18 No.8 18; No 19, 19th issue 19; 20th, 20th, 20th.