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:
<span>De dónde eres tú, Where are you from?</span>
5 is true 6 is also true
Estar is to be. But estar can be estoy, estas, esta, estamos, and estan. You can ask “Como estas” which is “how are you”
Estar is also used to express a person or item's geographic or physical location.
