What are these? (picture included)

Control of the body is accomplished by which of the following body systems? nervous system and circulatory system endocrine and repertory system circulatory and respiratory systems nervous system and endocrine systems

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

Which statement describes compounds a. compounds are made of one type of atom. b. compounds cannot be represented by models. c. compounds are represented by chemical formulas. d. compounds cannot be broken down into simpler forms.