Master Sgt. Jeremiah Fentress explains the proper way to take a temperature reading from a fuels sample to Afghan air force Lt. Mohammad Hamayoon and Sgt. Abdul Khalil during a basic fuels laboratory analysis training class at Kabul International Airport, March 5, 2012. In addition to analyzing fuels samples, students received specialized training needed to properly perform an American Petroleum Institute density test, Fuels System Icing Inhibitor test, Conductivity Unit test and an inline sample test. Fentress is a fuels advisor with the 439th Air Expeditionary Advisory Squadron. (U.S. Air Force photo/Staff Sgt. Nadine Y. Barclay)