Title: United States Air Force.
Question: What aircraft is used by the US Air Demonstration group The Thunderbirds?

Title: Royal assent.
Question: Who can be authorized to grant assent by letters patent?

Title: Infection.
Question: Recognizing the different characteristics of various diseases is one way to do what?

Title: Mary (mother of Jesus).
Question:
Who was visited by an angel in Sura 19 of the Qur'an?