Can someone please help me with this question please?

What are the most explosive events that occur on the sun? umbras solar flares solar winds prominences

Building glycogen from glucose molecules is an example of what

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point