39. What is the process of cooling or removing heat to lower the temperature of a space, or items to be stored in the space, to a temperature below the temperature of the surrounding area?
(A) Ventilation
(B) Refrigeration
(C) De-humidification
(D) Vaporization
39. What type of fire extinguisher can be used to extinguish electrical fire?
(A) CO2
fire extinguisher
(B) water fire extinguisher
(C) wet chemical fire extinguisher
(D) foam fire extinguisher
11. Which valve is used to prevent return or back-flow in pipe-lines and is automatically
operated?
(A) Check and stop valve
(B) Gate valve
(C) Globe valve
(D) Angle valve