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:
The answer for a is 1 and for b is 4 and c is 2 and d is 3. I know Spanish and I speak so it was pretty easy, hope this helps! A-1 b-4 c-2 d-3
Yo cumplo años el 26 de marzo
A.) El libro esta dentro de la mochila is the answer.
Hope it helped!!
IR- Yo- voy
Tú- vas
el ella usted- Va
nosotros- vamos
Vosotros- vivís
Ustedes- viven
ER
Example; Comer
Yo- como
Tu- comes
El ella- come
Nosotros- comemos
Vosotros- coméis
Ustedes- comen
Just focus on the last 2 letters
