上班时间内不应受（）等神经性刺激因素的干扰

21.Database synchronization is in progress

20.Install the valve and the correct gasket.

19.Make sure that the latch isfully engaged.

18.Holdthe cylinder tightly

17.Examine the seal for defects.

16.The control unit is installed aft of the cockpit.

15.Install the manifold

14.Documents must be readily revisable.

13.Deactivation/Reactivationprocedures for circuits,systems,units,etc,shall be included

12.The user of the schematicdiagram is the pilot