def make_query_url(url, items):
    """
    Take a URL base and a list of key/value pairs representing parameters,
    and convert them to a complete URL with those parameters in the query
    string.
    """
    str_items = ['{}={}'.format(*item) for item in items]
    if not str_items:
        return url
    else:
        return url + '?' + ('&'.join(str_items))