Answer:
The period of a wave is the time for a particle on a medium to make one complete vibrational cycle. Period, being a time, is measured in units of time such as seconds, hours, days or years. The period of orbit for the Earth around the Sun is approximately 365 days; it takes 365 days for the Earth to complete a cycle.
The answer is c you got to look for answers that make sense
13 year old and the light year mean cell of moucles that can use simple year light diffusion
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