Title: Madonna (entertainer).
Question: What instrument does Madonna play on her demo recordings?

Title: Korean War.
Question: Who was relieved from his duties as Commander in Korea?

Title: Printed circuit board.
Question: What element of a laminate is designated by the cloth to resin ratio, among other things?

Title: Botany.
Question:
What did the Angiosperm Phylogeny group use determine a phylogeny of flowering plants?