Listen to the statements and fill in the missing words in the blanks. 1. For ground operation, flight ________________ duties have been organized in accordance with an area of responsibility concept. 2. The captains and first officers have their ____________________. 3. All steps have to be performed prior to each originating flight or following a _____________maintenance action. 4. Any lights, which are not illuminated during a system test, will be checked by _______. The appropriate preflight procedures will be performed from memory. 5. ____________ are used only to verify that critical items affecting safety have been accomplished.