Question

If you see that a hot-air balloon is rising above the top of a hill, what is the top of the hill called? A. delta point B. distance system C. coordinate system D. reference point

Answer 1

If you see that a hot-air balloon is rising above the top of a hill,  the top of the hill is  called the reference point. Correct answer: D The reference point is a point (object, place) used for comparison to determine if something is in motion,  assuming that the reference point is stationary, or not moving.

Answer 2

The answer is reference point.