This means that it's sound is produced by the vibrations of a column of air.
(This; means; that it's sound is produced by the vibrations of a column of air) Context(This means,List([0, 10))):(it; 's; sound is produced by the vibrations of a column of air) Context(This means it 's,List([0, 20))):(sound; is produced; by the vibrations of a column of air)
This means,List([0, 10)) This means it 's,List([0, 20))
This it sound
means 's is produced
that it's sound is produced by the vibrations of a column of air
sound is produced by the vibrations of a column of air
by the vibrations of a column of air