Which sphere is most directly studied

by an astronomer

Witch type of microscope is used to view very small cell components like proteins and dna?

In a cladogram' when does a group of organisms branch off

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