Which part of the atmosphere is the highest layer in which planes can fly?

a. stratosphere b. thermosphere c. troposphere d. mesosphere

the stratosphere

Explanation:

Planes most commonly fly in the lower stratosphere to avoid turbulence which is common in the troposphere. little to no clouds appear in the stratosphere due to low humidity so it is easier to see.

15.3 cos 65 degrees trig

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.