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The conduction velocity of an axon is determined by myelin sheath
thickness and internode distance.
Axon are structures in the neuron which is involved in the conduction of
impulses away from the cell body. Axons which have myelin sheath conduct
impulses faster than those without it.
Axons which have thicker myelin sheath and longer internode distance will
increase the conduction velocity of an axon and vice versa.
Read more on brainly.com/question/23488967
Section 2 is right,, i think. good luck
Answer:
A vacuum
Explanation:
Sound waves are examples of mechanical waves. Mechanical waves are waves which are transmitted through the vibrations of the particles in a medium.
For example, sound waves in air consist of oscillations of the air particles, which vibrate back and forth (longitudinal wave) along the direction of propagation of the wave itself.
Given this definition of mechanical wave, we see that such a wave cannot propagate if there is no medium, because there are no particles that would oscillate. Therefore, among the choices given, the following one:
a vacuum
represent the only situation in which a sound wave cannot propagate through: in fact, there are no particles in a vacuum, so the oscillations cannot occur. In all other cases, instead, sound waves can propagate.