def construct_base_url(bible, text):
    """Return the base URL for BIBLE and TEXT. 
    BIBLE is 'KJV' or 'LEB'
    TEXT is 'xml' or 'json' or 'txt'
    """
    base_url = 'http://api.biblia.com/v1/bible/content/'
    url = base_url + bible + '.' + text
    return url