Final answer:
Motile cilia move substances such as mucus, dust particles, and microorganisms by rhythmically beating and pushing them towards the throat, either to be expelled or swallowed.
Step-by-step explanation:
Substances moved by the beating of motile cilia include mucus, dust particles, and microorganisms. Motile cilia are microscopic extensions of the apical cell membrane supported by microtubules, and they beat rhythmically to move these substances.
In the respiratory system, cilia help form a mucociliary escalator that traps dust and pathogens in mucus and sweeps them towards the throat, preventing them from reaching the lungs. Similarly, in the nasal passages, cilia move the mucus blanket containing trapped pathogens down towards the throat to be expelled or swallowed.