Answer:
the 2nd and the 3rd one depend on tense (past, present and future)
Explanation:
Scientists think that algae first evolved approximately 2.7 billion years ago, and soon after this oxygen began to exist in the atmosphere. Photosynthesis by primitive plants and algae released oxygen, which gradually built up in the atmosphere.
Explanation:
2nd but I’m not really sure
He lived "in the attic of the Smith household."
