21 Twenty-one
22 Twenty-two
23 Twenty-three
24 Twenty-four
25 Twenty-five
26 Twenty-six
27 Twenty-seven
28 Twenty-eight
29 Twenty-nine
30 Thirty
序数词
21 Twenty-first
22 Twenty-second
23 Twenty-third
24 Twenty-fourth
25 Twenty-fifth
26 Twenty-sixth
27 Twenty-seventh
28 Twenty-eighth
29 Twenty-ninth
30 Thirtieth