Answer:
Satellites orbit earth because of gravity
Answer:
Cell wall and chloroplasts, if you're comparing them to plant cells.
Explanation:
Plant cells have a harder protective wall around them, harder than the cell membrane. The animal cell doesn't have this.
Chloroplasts are organelles that takes the sunlight and turns it into energy for the plant cell. Animal cells don't have this for obvious reasons. We get our energy from food, not the sun.
I think it was space since the rivers were replaced with homes and birds have no where to go now.
Yes, because the speed is the same even if the body mass index is different.