Complex sentence: Byllye Yvonne Avery (born 1937) is an American health care activist, who has worked to improve the welfare of African-American women by creating the National Black Women's Health Project in 1981.
Split into simpler sentences: Byllye Yvonne Avery (born 1937) is a health care activist in the United States of America. She has worked to improve the welfare of African-American women by creating the National Black Women's Health Project in 1981.