The answer to that is c hope it helps
After my ythorough researching, the orbital velocity of the Earth compare to the Mercury is relative to each other. In addition, Mercury orbits the Sun and it is within the Earth's orbit as its lesser or inferior. The correct answer to the following given statement above is relative to each other.
The answer is b) false. Stars are mainly classified by their spectra (the elements they absorb) and their temperature.
The following apply:
Sound is a LONGITUDINAL wave.
Sound is a PRESSURE wave.
Longitudinal waves are waves in which the displacement of the medium is in the same direction as or opposite direction to the direction of wave propagation. An example of longitudinal wave is sound wave. Sound wave is also considered as a pressure wave as the result of the presence of repeating patterns of high and low pressure regions moving through a medium.