1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,30,40,50,60,70,80,90,的序数词英语咋写
依次first,second,third,fourth.fifth,sixth,senventh,eighth,ninth,tenth,eleventh,依此类推到nineteenth,然后，twentieth,thirtieth,fortieth,fiftieth,sixtieth,seventieth,eightieth,ninetieth
