What do astronomers use to calculate the age of the universe select 3 options

Ecosystems involve living organisms interacting with non-living things in a productive way; how is photosynthesis an example of this? answer, i will give brainiest to first person to get it right.

What are the possible blood types among the children of parents that are ab and ii? oa) types a and b ob) types a, b, and ab c) types a, b, and o od) types a, b, ab, and o

This is the main structural axis of the plant that supports leaves, flowers and fruits; transports fluids; stores nutrients and produces new tissue.