In northern latitudes, the temperature and air pressure were measured at a meteorological station, where the measuring

In northern latitudes, the temperature and air pressure were measured at a meteorological station, where the measuring instruments are enclosed in special closed containers. The readings of the thermometer and barometer turned out to be -42 C and 10 ^ 5Pa.
a) Name the bodies that form the thermodynamic system.
b) What will the readings of these devices be equal to if the parameters of the thermodynamic system have not changed?
c) What liquid is used for the manufacture of thermometers that measure the air temperature outside?

a) Air in the container, barometer and thermometer,
b) T = -42 ° C p = 10 ^ 5 Pa
c) mercury or alcohol.