In terms of action-reaction force pairs, explain why it is important to use helmets, elbow pads, knee pads and other protective clothing while using skateboards or in-line skates

the independent variable, or the one that is intentionally manipulated is the speed.

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.

statement #3 on andre"s list is false.

answerdmitry mendeleyev made a workable classification of the elements