Why is pluto so different from other outer planets

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 could be a pathway of food through an ecosystem

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above