I believe the answer is B
I need the choices to be able to help you...
Answer:
Changes in the pressure create the flow of the air to move up and down in the ear and thus create popping sound.
Explanation:
- The ear-popping is caused by the phenomenon of the opening of the Eustachian tube when one swallows and it might be automatically when you blow our nose or are setting in an airplane and this sound is created when the air enters the middle ear through the tube.
For continental U.S. the answer is never. Since the earth's rotation axis is tilted 23.5 degrees with respect to its orbital motion around the su, one would have to be less than 23.5 degrees above or below the equator to have the sun pass direclty overhead
