基數(shù)詞：
1 one
2 two
3 three
4 four
5 five
6 six
7 seven
8 eight
9 nine
10 ten
11 eleven
12 twelve
13 thirteen
14 fourteen
15 fifteen
16 sixteen
17 seventeen
18 eighteen
19 nineteen
20 twenty
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
31 thirty-one
32 thirty-two
33 thirty-three
34 thirty-four
35 thirty-five
36 thirty-six
37 thirty-seven
38 thirty-eight
39 thirty-nine
40 forty