Return the math words for a language code.
    The language_code should be an ISO 639-2 language code.
    https://www.loc.gov/standards/iso639-2/php/code_list.php

def words_for_language(language_code):
    """
    Return the math words for a language code.
    The language_code should be an ISO 639-2 language code.
    https://www.loc.gov/standards/iso639-2/php/code_list.php
    """
    word_groups = word_groups_for_language(language_code)
    words = []

    for group in word_groups:
        words.extend(word_groups[group].keys())

    return words