Complex sentence: Alongside his work in cinema, Norton is an environmental and social activist, and is a member of the board of trustees of Enterprise Community Partners, a non-profit organization for developing affordable housing founded by his grandfather James Rouse.
Split into simpler sentences: Alongside his work in cinema, Norton is an environmental and social activist. He is a member of the board of trustees of Enterprise Community Partners, a non-profit organization for developing affordable housing founded by his grandfather James Rouse.