Title: Wood.
Question: Does a tree growing quickly out in the open have thinner or thicker sapwood for its size than the same kind of tree in a dense forest?

Title: Madonna (entertainer).
Question: Who did Madonna tell in an interview that as a young girl, she was lonely and always searching for something?

Title: Gene.
Question: What is one exception to the central dogma of molecular biology?

Title: Middle Ages.
Question:
About how many millions of people lived in Europe in the year 1000?