In measuring pressure, what does "psi" stand for?

Which unit used in commerce equals 42 gallons of crude oil? Which unit of distance equals 220 yards, or one-eighth of a mile? Which unit of energy does the abbreviation kWh stand for? What is a local unit of Girl Scouts called? Which United Nations agency is known by the initials WHO? Which English city's "United" soccer club plays its home games at Old Trafford? A U.S. Army officer with one star holds which rank? U.S. courts ruled in the late 1990s that statistical sampling could not be used to apportion House seats in which 2000…