Lol it’s the first one :)
Answer:
Air pressure is caused by the weight of the air molecules above
Explanation:
Air pressure is caused by the weight of the air molecules above. Even tiny air molecules have some weight, and the huge numbers of air molecules that make up the layers of our atmosphere collectively have a great deal of weight, which presses down on whatever is below.
I believe this difference in concentration of dissolved Particles from one location to another is called a concentration gradient.
Answer:
speed = distance/ time= 45/3 = 15miles per hour
Explanation: