1-20英语序数词怎么背诵?答:1-10序数词:first. second. third. fourth. fifth. sixth. seventh. eighth. ninth. tenth.11-19序数词: eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, nineteenth.21-29序数词:twenty-first, twenty-second, twenty-third, twenty-fourth, twenty-fifth...