I think a, im not a 100% sure tho!!!
Basically its just an air like fluid with chemicals.... just like air it just goes as it pleases and fills space
Answer: 
Explanation:
Acceleration 
is expressed in the following formula:
Where:
is the final velocity of the projectile
is the initial velocity of the projectile
is the time
Solving:
This is the acceleration of the projectile
A. Radio waves
Have the lowest frequencies
Answer:
The coastal regions are affected by abrasion due to large volumes of water and increased winds. This can become more severe especially with storms that hit coastal regions.
Explanation:
Abrasion is physical weathering caused by water, wind and gravity. Hope it worked, I love geography! Can you mark mine as the brainliest please! Also can you give me a thanks and a 5 star vote!
