Question

the air pressure system, vibratory system, and resonating system are all

parts of a pa system

acting techniques

subsystems of the voice mechanism

tools for actors to use for practice

Explanation:

The air pressure system (lungs), vibratory system (vocal cords), and resonating system (oral cavity, nasal cavity etc.) are all parts of how the human voice is produced. A PA system is a public - address system (electrical equipment), acting techniques are broader skills like emotional recall etc., and while actors may practice voice - related things, these are specifically subsystems of the voice mechanism.

Answer:

subsystems of the voice mechanism