They may be changed because they may find evidence of some thing that will change their perspective on things.
A. Using a combination lens made up of lenses, each of which has a different index of refraction. Is the correct answer.
They are both created by waves of different forms of energy... sound is the oscillation of other substances, called a medium, while the electromagnetic waves are oscillating through electromagnetic energy.
There's no air in space, so there's no air resistance there.
It is an example of reflection of wave. C.
