Jeopardy for the classroom

Twelve

1. In the American judicial system, how many members does a jury usually have?
2. What large ocean liner sank in the North Atlantic in April, 1912, after striking an iceberg?
3. Twelve o'clock can be said two special ways, one meaning 12 a.m. and the other 12 p.m. What are these two special words?
4. What "counter" in English is equivalent to 12 of something? It is often used to describe a set of 12 eggs.
5. In the West, astrologers divide the year into twelve periods of time, giving each period a different sign such as Cancer, Pisces, or Gemini. What are these twelve signs called as a group?