Answer:
1.Atria push blood into the ventricles
2.Venticles push blood out of the heart.
D. Tundra as it is below the Equator and warm, there is the amazon rainforest and grassland is rural areas and well as Savannahs’ which are relatively close to grassland
Answer:
Many things, such as weather change, migration cycles being thrown off, droughts, floods, and more