Why is a mobile home an unsafe place to be during a tornado

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

What is the statement plant growth is affected by the color light

Which group of molecules are targeted by the kinases in order to control this movement