His mother's birthday is on December __the__ ___twenty__ __fourth___.
如果两个空的话应该是
His mother's birthday is on December __the__ ___twenty-fourth__.
应该没错
His mother's birthday is on December __the__ ___twenty__ __fourth___.
如果两个空的话应该是
His mother's birthday is on December __the__ ___twenty-fourth__.
应该没错