Four lighthouses have been built on the Eddystone Rocks off Plymouth, England, which were long notorious for causing what?

Which actor played Sherlock Holmes opposite Jude Law's Dr. Watson in the 2009 film? The year 2010 saw the 40th anniversary of which environmental observance? Count Dooku, played by Christopher Lee in the "Star Wars" prequels, took which Sith name? Ray Mercer, Ray Seales and which other "Ray" won Olympic boxing gold medals for the U.S.? Which mineral of silicon dioxide keeps time in many watches because it vibrates at a precise frequency when electricity… In the 9th century, Viking invaders set up the Danelaw, an area of which country in which Danish law was supreme? A believer in Gandhian nonviolence, pacifist A.J. Muste helped found which civil rights group in 1942? Which word for a bishop's tall headdress also names a corner joint where two pieces meet at 45-degree angles?