Answer:
b because I learned it in 4th grade
Explanation:
b
Elements that have atoms with full outer shells of electrons
Are inert
Answer:
An ecosystem exists within a biome. Biomes are home to many species of animals, which interact with one another to create an ecosystem.
Explanation:
An ecosystem is defined as "the interaction of plants and animals with nonliving things and each other." A biome is defined as "a large region of the world that has similar plants, animals and other organisms that are adapted to the terrain and weather of that region."
Answer: the earth was just starting to develop really well and well enough for life.
Explanation: atmospheric oxygen and oceanic calcium levels went up, but nobody needs to know that much facts about how earth developed, But the group called phyla started growing because of these conditions
