Sound waves require a medium. For example - think about space. there is no air or liquid because it is a vacuum, which is why sounds don’t travel through space.
The grommets on your shoe (Holes through which you place the lace) act as the pulley. When you tighten at the top it restricts at the bottom and compresses around your foot.
The same can be applied to a pulley; If you have the proper set up Pulling one string causes two actions; the first being the most obvious. And the second being its effect. The Grommets of your shoe are the pulley's; while your Shoelaces are just the rope with which you operate the pulley.
Answer:
It would be C
Explanation:
The brain operates on two levels, one of them is unconscious.
