Which of the following structures are regions of the lungs? a. apex, base, hilum b. cilia, adenoids, mucous, epiglottis c. frontal, maxillary, sphenoidal, ethmoidal d. eustachian, pharynx, bronchi

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.

grav forces affect all objects magnetic forces affect magnetic objects and electric currents