1. its must be B and 2. must be C
<span>The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object. Hope this helped.</span>
To determine what the cyclists average speed is, simply divide the distance the cyclist has travelled by the time the cyclist has traveled for.
Assuming that this is the average rate the cyclist is moving at it would be 12 km/hr.
Decibels I believe? I’m not 100% sure