Title: Geological history of Earth.
Question: Glaciars from what period depressed the height of northern lands by 591 feet?

Title: Geography of the United States.
Question: Which region experiences the worst droughts in the US?

Title: Gregorian calendar.
Question: With what did the Calendar Act align the British calendar?

Title: Sexual orientation.
Question:
What is causing contreversy as to the concept of sexual orientation?