def build_annual_urls(first_url,year):
    """
    This method takes the first SD url and creates a list of
    urls which lead to the following pages on SD which will be
    scraped. The page list is for a given year.

    Parameters
    ----------
    first_url (str) : The URL from ScienceDirect after searching for desired
        keywords

    year (str or int) : The given year the URL list is being built for


    Returns
    -------
    page_urls (list) : List of urls the webdriver will use to access all
        available pages for a given year on a given topic

    """

    page_urls = []
    for i in range(20):
        url_100 = first_url.replace('&show=25','&show=100')
        urli = url_100 + '&offset=' + str(i) + '00' + '&articleTypes=REV%2CFLA' + '&years=' + str(year)
        page_urls.append(urli)

    return page_urls