Explanation
Smoke purging, smoke removal, smoke exhaust, or smoke extraction are different terms for the same type of smoke management method, which is airflow. Airflow is the method of controlling smoke by creating a flow of air that either pushes or pulls the smoke away from the desired areas. Airflow can be achieved by natural or mechanical means, such as vents, fans, or dampers. Airflow can also be used to create a smoke layer above the occupant level in large spaces, such as atriums or warehouses, by exhausting the hot smoke and supplying fresh air below the layer.References:Smoke Extraction System - NAFFCO Smoke Management;Post-Fire Smoke Purge Systems: When Are They Required? - NY Engineers; NFPA Fire Protection Handbook, 21st Edition, Chapter 9, Section 9.2.1.

Explanation
The measurement of a fluid's resistance to flow is calledviscosity.Viscosity is the property of a fluid that describes how easily it can deform or move when subjected to a shear stress, such as the force exerted by a pipe wall or a pump1. A fluid with high viscosity, such as honey, resists flow and requires more pressure to overcome the friction between its layers.A fluid with low viscosity, such as water, flows easily and has less frictional resistance2.Viscosity affects the hydraulic properties of water for fire protection systems, such as the flow rate, pressure loss, and pump power3. Viscosity is usually expressed in units of pascal-second (Pa s) or centipoise (cP) for liquids, and is dependent on the temperature and composition of the fluid.References:
Viscosity | Definition, Facts, Formula, Units, & Examples
Viscosity - The Physics Hypertextbook
Fire Pump Types | NFPA
[12.4: Viscosity and Laminar Flow; Poiseuille's Law]

Explanation

Hazardous waste
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The correct answer is C. Environmental Protection Agency (EPA) standards require solid waste be treated as hazardous if it is a listed waste and/or meets the characteristics prescribed by the standard for toxicity, reactivity, corrosivity, andignitability.A listed waste is a waste that appears on one of the four lists of hazardous wastes in the Code ofFederal Regulations (CFR) part 261 subpart D1.A characteristic waste is a waste that exhibits one or more of the following traits: toxicity, reactivity, corrosivity, or ignitability2.
Toxicity is the ability of a waste to leach harmful chemicals into the environment. Reactivity is the tendency of a waste to undergo violent chemical reactions or generate toxic gases. Corrosivity is the property of a waste to corrode metals or damage living tissues.Ignitability is the capacity of a waste to catch fire under certain conditions2.These characteristics are defined by specific tests and criteria in the CFR part 261 subpart C3.The EPA standards for hazardous waste are based on the Resource Conservation and Recovery Act (RCRA), which is the federal law that regulates the management of solid and hazardous waste in the United States4.

Explanation

Fire pump
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The correct answer is B.Safety is one of the criteria for selecting the power source for driving fire pumps, according to NFPA 20, Chapter 9.1.1.11. Reliability, adequacy, and economy are the other criteria mentioned in the same chapter. Efficiency, adaptability, and ecology are not explicitly stated as criteria in NFPA 20, although they may be considered as secondary factors in some cases.
1:Pump Installation: Everything About Electric and Diesel Driven Fire ...

Explanation
According to the web search results, the goals of the first edition of NFPA 13D were to provide sufficient time for safe egress or rescue, economic viability, and limit damage to the dwelling. The first edition of NFPA 13D was published in 1975 and was based on the concept of a "life safety" sprinkler system that was intended to protect the occupants of one- and two-family dwellings and manufactured homes from fire.The first edition of NFPA 13D stated that the system was not designed to protect the property or contents from fire damage, but rather to provide a tenable environment for escape or rescue1.The first edition of NFPA 13D also recognized the need for economic viability of the system, and therefore allowed for reduced water supply and piping requirements compared to other sprinkler standards2.The first edition of NFPA 13D did not explicitly state the goal of limiting damage to the dwelling, but it implied that the system would have some beneficial effect on the fire spread and severity by stating that the system was designed to prevent flashover in the room of fire origin1.References:
NFPA 13D: Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes, 1975 Edition, Section 1-11 Fire Protection Handbook, 20th Edition, Volume 1, Chapter 8, Section 8.2.1.22