Final answer:
The two key themes from the 1980s to 1990s are Element Public Space and Element Interwoven, reflecting a shift towards minimalist and Postmodern architecture that focused on simplicity, essential quality, and the interweaving of historical elements.
Step-by-step explanation:
The two key themes from the 1980s to 1990s in relation to architecture and urban design are Element Public Space and Element Interwoven. These themes are reflected in the trend of minimalist architecture that became popular in the late 1980s, characterized by simplicity, open spaces, and a focus on the essential quality of buildings. Furthermore, the late 20th century also saw a shift towards Postmodern architecture, which embraced ornamentation and historical references, thus interweaving past and present design elements. The era was marked by attempts to bring together multiple functions and infrastructure within urban spaces, making them more efficient and catered to public needs, including integration with public transportation systems and adapting to energy requirements.