Which muscle is the women using to lift the ball over her head

Will someone me with this.. specialized cells which perform a particular function form: tissues organs or organism

Coral reefs support more species per unit area than any other marine environment on earth. what is one way coral reefs are important to the health of the biosphere

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