Some FAQ in translation.

012 ----> 012  (no replacement)
thirty\none ---> 30\n1
1\n3  ---> one\nthree
31abc ---> 31abc (no replacement)
4.5 ---> 4.5 (no replacement)
31  ---> thirty one (lower case separated by one blank)
thirty one? ---> 30 one? (one? is not replaced)
Y2K  ---> Y2K (no replacement)
ThirTy ---> 30 (case insensitive)

Note: Beginning of the file does not separate a token.