Which unit of energy does the abbreviation kWh stand for?

How many sides does a typical snowflake have? Which number of degrees means a U-turn or a complete reversal of opinion? Which unit used in commerce equals 42 gallons of crude oil? Which unit of distance equals 220 yards, or one-eighth of a mile? What is a local unit of Girl Scouts called? In measuring pressure, what does "psi" stand for? Which United Nations agency is known by the initials WHO? Which English city's "United" soccer club plays its home games at Old Trafford?