1.  All conductive objects such as cables, track, trolley wire, water lines, belt structures, etc., extending into the _________ area should be severed or removed at or outby the fresh-air base before explorations are started.

2.  Explosions in coal mines are most often caused by _________ of methane, coal dust, or a combination of the two.

3.  An indication of an _________ may be a jump in the pressure recording chart for the main fan.

4.  Gas readings must be taken in the __________ near the fire area to determine if the mine atmosphere is potentially explosive.

5.  Seals in high volatile coalbeds are often placed _________ feet or more from the fire area.

6.  When sealing a mine _________, you should be careful to ensure that there are no abrupt changes in the ventilation over the fire area.

7.  Non-metallic sampling pipes are inserted in temporary and permanent seals for the purpose of _________ air samples from the sealed area.

8.  Before going underground to __________ for a fire or to fight a fire, the team should know about any possible ignition sources that may exist in the affected area.

9.  The team should make sure the main fan is __________, a guard is monitoring the operation of the fan, and that tests are being made at the main return for any gases that may be present in the mine, before they go underground.

10.  Before a fresh-air base is ___________, gas tests should be made in all dead ends and high places between the old and new fresh-air base.