Easy
1: o _ e
one
nine
14: f _ ur _ ee _
fourteen
eight
3: th _ ee
three
six
11: _ l _ v _ n
eleven
13: _ _ _ r _ _ _ _
thirteen
7: s _ ven
seven
12: tw _ lv _
twelve
19: ni _ e _ e e _
nineteen
18: _ _ _ h _ _ _ _
eighteen
10: t _ n
ten
15: fif _ ee _
fifteen
20: t _ e _ t _
twenty
2: _ _ _
two