Is there anything else that goes with this question? I’m not sure how to answer.
The tissues found within the vein if I must say are xylem and phloem. Glad I can help.
A- Flatworms are unsegmented and only have one mouth/anus opening. And they are obviously flat
Answer:
Volcanic degassing of volatiles, including water vapour, occurred during the early stages of crustal formation and gave rise to the atmosphere. When the surface of Earth had cooled to below 100 °C (212 °F), the hot water vapour in the atmosphere would have condensed to form the early oceans.
Explanation:
