What is one advantage of prezygotic isolation over postzygotic isolation?

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

Hurry where is the majority of earth's water found? o glaciers o oceans ground o rivers and lakes

Which enzymes break down carbohydrates?