Answer:
UFOs
Explanation:
Try to present something about UFOs since you are learning about aliens! Describe evidence we know, some sightings, and your belief.
Answer:
Plants, animals, or pathogens that are non-native (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause harm.”
Explanation:
so, yes
The gradual abundance of oxygen (by product of photosynthesis) made it possible for aerobic organisms to grow more and evolve.
Hope that helps!
The Earth was first considered habitable when we discovered that it was Microbial organisms that started the process. I would go with D.
