Lookup functions allow spreadsheet users to show quantities of distinct, discrete categories of data.
present data that changes as a function of time.
keep track of IF statements and nested IF statements.
reduce the amount of manual searching and data entry.

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.

elctricity and magnet is conversion to it

3. dark matter

empty space could also be a simple vacuum