Which two-letter initials name the numeric address that identifies each device on the Internet?

Which 1973 Pink Floyd album shares its name with a popular term for the lunar far side, first photographed by Luna 3 in… 41 years after "On the Waterfront", which actor played Johnny Depp's psychiatrist in 1995's "Don Juan DeMarco"? In AD 410, under Alaric, which Germanic people sacked Rome? 42 U.S. gallons of crude oil equal one of what? Which war was fought in ancient Greece from 431 to 404 BC? 4,389-foot Cerro de Punta is the highest point on which Caribbean island, a U.S. territory? Who began his account of the Gallic Wars with "All Gaul is divided into three parts"? Which GM in-vehicle service, launched in 1996, offers emergency help and navigation at the push of a button?