The dictionary definiton of light is:
the natural agent that stimulates sight and makes things visible.
I'll paraphrase/give a scientific definition:
Light is made of subatomic particles called photons, which jumps electron shells when they're excited, effecting the electromagnetic spectrum, creating visible light.
Hope this helps. Might not as I'm not perfect on this topic yet.
The answer is D but I gotta make this answer 20 characters real quick so ignore what I'm saying ja ja ja the cat go wow the I guess on this and I answer it a but the dog go wolf wolf moo
Accelerating, because it’s going from standing still to running, so the speed increases
The answer is B. The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume.