Which is a prokaryotic cells - onion root , cows liver , human blood , e. coli

What are some characteristics of a free enterprise economy?

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?

Johnny rode his bike 4 blicks down the street to his friend's house once he got to his friend house and realized he could not cone out to play he turned aroubd and went back home.what is 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