Given the following.

Rescue apparatus	Characteristic
P. Draeger BG-4	1. Open circuit chemical oxygen self-rescuer
Q. MSA IW-65	2. Filter type self-rescuer
R. Draeger Pulmotor	3. Self-contained breathing apparatus
S. Oxvoks	4. Resuscitation apparatus

The correct match is

The liquid employed in aneroid barometer.

The mechanical mixture of gases existing in a mine given off after explosion called

A Drager Gas Mask does not filter

The resistances of two splits A and Bare 0.35 Ns²m^-8 and 0.05 Ns²m^-8 respectively. The combined resistance of the shafts and trunk airways is 0.4 Ns²m^-8. A booster fan is planned to be installed in split A to increase the quantity flowing through it. Assuming that the surface fan continues to operate at a constant pressure of 1000 Pa, the critical pressure of the booster fan in Pa is